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 (
    82585, 86129, 86130, 86152, 86153, 85099, 
    85296, 85298, 85393, 85395, 85444, 
    85446, 85495, 85497, 89805, 89857, 
    89929, 91495, 85047, 89824, 89876, 
    89948, 91514, 82832
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00080

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "10.82"
    },
    "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": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "8.42",
        "eval_cost": "2.40",
        "prefix_cost": "10.82",
        "data_read_per_join": "91K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (82585,86129,86130,86152,86153,85099,85296,85298,85393,85395,85444,85446,85495,85497,89805,89857,89929,91495,85047,89824,89876,89948,91514,82832)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
82585 nuie Arno 800mm Floor Standing 2-Door Vanity & Curved Basin - Gloss White
82832 nuie Arno 600mm Wall Hung 2-Drawer Vanity & Minimalist Basin - Solace Oak
85047 Hudson Reed Fluted 600mm Floor Standing 2-Door Vanity and Thin-Edge Basin - Satin White
85099 Hudson Reed Fluted 500mm Wall Hung 2-Drawer Vanity and Thin-Edge Basin - Satin White
85296 nuie Deco 600mm Wall Hung 2-Drawer Vanity & Thin-Edge Basin - Satin Anthracite
85298 nuie Deco 600mm Wall Hung 2-Drawer Vanity & Curved Basin - Satin Anthracite
85393 nuie Deco 600mm Wall Hung 2-Drawer Vanity & Thin-Edge Basin - Satin Grey
85395 nuie Deco 600mm Wall Hung 2-Drawer Vanity & Curved Basin - Satin Grey
85444 nuie Deco 600mm Wall Hung 2-Drawer Vanity & Thin-Edge Basin - Satin Blue
85446 nuie Deco 600mm Wall Hung 2-Drawer Vanity & Curved Basin - Satin Blue
85495 nuie Deco 600mm Wall Hung 2-Drawer Vanity & Thin-Edge Basin - Satin Green
85497 nuie Deco 600mm Wall Hung 2-Drawer Vanity & Curved Basin - Satin Green
86129 Hudson Reed Havana Wall Hung 2 Drawer Vanity Basin Unit & Thin-Edge Ceramic Basin, 500mm - Graphite Grey
86130 Hudson Reed Havana Wall Hung 2 Drawer Vanity Basin Unit & Curved Ceramic Basin, 500mm - Graphite Grey
86152 Hudson Reed Havana Wall Hung 2 Drawer Vanity Basin Unit & Thin-Edge Ceramic Basin, 500mm - Coastal Grey
86153 Hudson Reed Havana Wall Hung 2 Drawer Vanity Basin Unit & Curved Ceramic Basin, 500mm - Coastal Grey
89805 Hudson Reed Urban Wall Hung 2 Drawer Vanity Unit with Mid-Edge Basin 600mm - Satin Grey
89824 Hudson Reed Urban Wall Hung 2 Drawer Vanity Unit with Bellato Grey Worktop 800mm - Satin Grey
89857 Hudson Reed Urban Wall Hung 2 Drawer Vanity Unit with Mid-Edge Basin 600mm - Satin Blue
89876 Hudson Reed Urban Wall Hung 2 Drawer Vanity Unit with Bellato Grey Worktop 800mm - Satin Blue
89929 Hudson Reed Urban 600mm Wall Hung 2-Drawer Unit and Mid-Edge Basin 1 Tap Hole - Satin Green
89948 Hudson Reed Urban 800mm Wall Hung 2-Drawer Unit and Laminate Top - Satin Green
91495 Hudson Reed Urban Wall Hung 2 Drawer Vanity & Mid-Edge Ceramic Basin, 600mm - Satin Anthracite
91514 Hudson Reed Urban Wall Hung 2 Drawer Vanity & Laminate Worktop, 800mm - Satin Anthracite/Bellato Grey