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 (
    87330, 87331, 87342, 87343, 82600, 83076, 
    83629, 90912, 90991, 86638, 86707, 
    82717, 83455, 85086, 85172, 85218, 
    85264, 83079, 83080, 83577, 83579, 
    90916, 90918, 90995
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.18"
    },
    "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": "10.78",
        "eval_cost": "2.40",
        "prefix_cost": "13.18",
        "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 (87330,87331,87342,87343,82600,83076,83629,90912,90991,86638,86707,82717,83455,85086,85172,85218,85264,83079,83080,83577,83579,90916,90918,90995)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
82600 nuie Arno 1200mm Wall Hung 2-Drawer Vanity & Worktop - Gloss White
82717 nuie Arno 800mm Floor Standing 2-Drawer Vanity & Minimalist Basin - Gloss White
83076 nuie Arno 800mm Wall Hung 2-Drawer Vanity & Worktop - Satin Green
83079 nuie Arno 600mm Floor Standing 2-Drawer Vanity & Thin-Edge Basin - Satin Green
83080 nuie Arno 600mm Floor Standing 2-Drawer Vanity & Curved Basin - Satin Green
83455 nuie Athena Floor Standing 2 Drawer Vanity With Minimalist 1 Tap Hole Ceramic Basin 800mm - Gloss White
83577 nuie Athena Floor Standing 2 Drawer Vanity With Thin-Edge 1 Tap Hole Ceramic Basin 600mm - Gloss Grey
83579 nuie Athena Floor Standing 2 Drawer Vanity With Curved 1 Tap Hole Ceramic Basin 600mm - Gloss Grey
83629 nuie Athena Wall Hung 2 Drawer Vanity With Worktop 800mm - Gloss Grey
85086 Hudson Reed Fluted 800mm Wall Hung 2-Drawer Vanity and Worktop - Satin Anthracite
85172 Hudson Reed Fluted 800mm Wall Hung 2-Drawer Vanity and Worktop - Satin Grey
85218 Hudson Reed Fluted 800mm Wall Hung 2-Drawer Vanity and Worktop - Satin Blue
85264 Hudson Reed Fluted 800mm Wall Hung 2-Drawer Vanity and Worktop - Satin Green
86638 Hudson Reed Juno 1200mm Wall Hung 4-Door Vanity & Worktop - Graphite Grey
86707 Hudson Reed Juno 1200mm Wall Hung 4-Door Vanity & Worktop - Coastal Grey
87330 nuie Lunar Wall Hung 2 Drawer Unit & Polymarble Basin, 600mm - Satin Blue
87331 nuie Lunar Wall Hung 2 Drawer Unit & Ceramic Basin, 600mm - Satin Blue
87342 nuie Lunar Wall Hung 2 Drawer Unit & Polymarble Basin, 600mm - Satin Green
87343 nuie Lunar Wall Hung 2 Drawer Unit & Ceramic Basin, 600mm - Satin Green
90912 nuie Arno Wall Hung 2 Drawer Vanity & Laminate Worktop, 800mm - Satin Anthracite
90916 nuie Arno Floor Standing 2 Drawer Vanity & Thin-Edge Ceramic Basin, 600mm - Satin Anthracite
90918 nuie Arno Floor Standing 2 Drawer Vanity & Curved Ceramic Basin, 600mm - Satin Anthracite
90991 nuie Arno Wall Hung 2 Drawer Vanity & Laminate Worktop, 800mm - Satin Grey
90995 nuie Arno Floor Standing 2 Drawer Vanity & Thin-Edge Ceramic Basin, 600mm - Satin Grey