SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    86510, 86665, 86734, 86786, 83056, 83605, 
    90892, 90971, 85106, 85107, 89824, 
    89876, 89948, 91514, 83059, 83608, 
    90895, 90974, 85322, 85419, 85470, 
    85521, 82635, 83532, 85065, 85151, 
    85197, 85243, 82838, 82839, 82911, 
    82912, 82984, 82985, 83398, 83399, 
    83408, 83409, 85368, 86137, 86160, 
    86645, 86714, 82857, 82930, 83003, 
    83519, 83527
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00102

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "25.69"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "20.89",
        "eval_cost": "4.80",
        "prefix_cost": "25.69",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (86510,86665,86734,86786,83056,83605,90892,90971,85106,85107,89824,89876,89948,91514,83059,83608,90895,90974,85322,85419,85470,85521,82635,83532,85065,85151,85197,85243,82838,82839,82911,82912,82984,82985,83398,83399,83408,83409,85368,86137,86160,86645,86714,82857,82930,83003,83519,83527)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
82635 nuie Arno 800mm Wall Hung 2-Drawer Vanity & Laminate Top - Gloss White
82838 nuie Arno 600mm Wall Hung 2-Drawer Vanity & Laminate Top - Solace Oak
82839 nuie Arno 600mm Wall Hung 2-Drawer Vanity & Laminate Top - Solace Oak
82857 nuie Arno 800mm Wall Hung 2-Drawer Vanity & Worktop - Solace Oak
82911 nuie Arno 600mm Wall Hung 2-Drawer Vanity & Laminate Top - Anthracite
82912 nuie Arno 600mm Wall Hung 2-Drawer Vanity & Laminate Top - Anthracite
82930 nuie Arno 800mm Wall Hung 2-Drawer Vanity & Worktop - Anthracite
82984 nuie Arno 600mm Wall Hung 2-Drawer Vanity & Laminate Top - Charcoal Black
82985 nuie Arno 600mm Wall Hung 2-Drawer Vanity & Laminate Top - Charcoal Black
83003 nuie Arno 800mm Wall Hung 2-Drawer Vanity & Worktop - Charcoal Black
83056 nuie Arno 600mm Wall Hung 2-Drawer Vanity & Laminate Top - Satin Green
83059 nuie Arno 600mm Wall Hung 2-Drawer Vanity & Worktop - Satin Green
83398 nuie Athena Wall Hung 2 Drawer Vanity With Sparkling Black Worktop 600mm - Anthracite Woodgrain
83399 nuie Athena Wall Hung 2 Drawer Vanity With Sparkling White Worktop 600mm - Anthracite Woodgrain
83408 nuie Athena Wall Hung 2 Drawer Vanity With Sparkling Black Worktop 600mm - Hacienda Black
83409 nuie Athena Wall Hung 2 Drawer Vanity With Sparkling White Worktop 600mm - Hacienda Black
83519 nuie Athena Wall Hung 2 Drawer Vanity With Worktop 800mm - Anthracite Woodgrain
83527 nuie Athena Wall Hung 2 Drawer Vanity With Worktop 800mm - Hacienda Black
83532 nuie Athena Wall Hung 2 Drawer Vanity With Grey Worktop 800mm - Gloss White
83605 nuie Athena Wall Hung 2 Drawer Vanity With Grey Worktop 600mm - Gloss Grey
83608 nuie Athena Wall Hung 2 Drawer Vanity With Worktop 600mm - Gloss Grey
85065 Hudson Reed Fluted 600mm Wall Hung 2-Drawer Vanity and Laminate Top - Satin Anthracite
85106 Hudson Reed Fluted 600mm Wall Hung 2-Drawer Vanity and Laminate Top - Satin White
85107 Hudson Reed Fluted 600mm Wall Hung 2-Drawer Vanity and Laminate Top - Satin White
85151 Hudson Reed Fluted 600mm Wall Hung 2-Drawer Vanity and Laminate Top - Satin Grey
85197 Hudson Reed Fluted 600mm Wall Hung 2-Drawer Vanity and Laminate Top - Satin Blue
85243 Hudson Reed Fluted 600mm Wall Hung 2-Drawer Vanity and Laminate Top - Satin Green
85322 nuie Deco 800mm Wall Hung 2-Drawer Vanity & Worktop - Satin Anthracite
85368 nuie Deco 800mm Wall Hung 2-Drawer Vanity & Worktop - Satin White
85419 nuie Deco 800mm Wall Hung 2-Drawer Vanity & Worktop - Satin Grey
85470 nuie Deco 800mm Wall Hung 2-Drawer Vanity & Worktop - Satin Blue
85521 nuie Deco 800mm Wall Hung 2-Drawer Vanity & Worktop - Satin Green
86137 Hudson Reed Havana Wall Hung 2 Drawer Unit & Laminate Worktop, 600mm - Graphite Grey/Bellato Grey
86160 Hudson Reed Havana Wall Hung 2 Drawer Unit & Laminate Worktop, 600mm - Coastal Grey/Bellato Grey
86510 Hudson Reed Juno 600mm Wall Hung 2-Drawer Vanity & Worktop - Autumn Oak
86645 Hudson Reed Juno 600mm Wall Hung 2-Drawer Vanity & Laminate Top - Graphite Grey
86665 Hudson Reed Juno 800mm Wall Hung 2-Drawer Vanity & Worktop - Graphite Grey
86714 Hudson Reed Juno 600mm Wall Hung 2-Drawer Vanity & Laminate Top - Coastal Grey
86734 Hudson Reed Juno 800mm Wall Hung 2-Drawer Vanity & Worktop - Coastal Grey
86786 Hudson Reed Juno Wall Hung 2 Drawer Vanity Unit & Colour Match Worktop, 600mm - Metallic Slate
89824 Hudson Reed Urban Wall Hung 2 Drawer Vanity Unit with Bellato Grey Worktop 800mm - Satin Grey
89876 Hudson Reed Urban Wall Hung 2 Drawer Vanity Unit with Bellato Grey Worktop 800mm - Satin Blue
89948 Hudson Reed Urban 800mm Wall Hung 2-Drawer Unit and Laminate Top - Satin Green
90892 nuie Arno Wall Hung 2 Drawer Vanity & Laminate Worktop, 600mm - Satin Anthracite/Bellato Grey
90895 nuie Arno Wall Hung 2 Drawer Vanity & Laminate Worktop, 600mm - Satin Anthracite
90971 nuie Arno Wall Hung 2 Drawer Vanity & Laminate Worktop, 600mm - Satin Grey/Bellato Grey
90974 nuie Arno Wall Hung 2 Drawer Vanity & Laminate Worktop, 600mm - Satin Grey
91514 Hudson Reed Urban Wall Hung 2 Drawer Vanity & Laminate Worktop, 800mm - Satin Anthracite/Bellato Grey