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 (
    88143, 88508, 87890, 84695, 88937, 87877, 
    87905, 88045, 88049, 87936, 88515, 
    88518, 88078, 88514, 88517, 88511, 
    88083, 87904, 90325, 87876, 88506, 
    88507, 88510, 88035
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00065

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 (88143,88508,87890,84695,88937,87877,87905,88045,88049,87936,88515,88518,88078,88514,88517,88511,88083,87904,90325,87876,88506,88507,88510,88035)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
84695 Hudson Reed Solar 600mm Ceramic 1 Tap Hole Basin - White
87876 nuie Mayford Round Ceramic 1 Tap Hole Basin 750mm
87877 nuie Mayford Round Ceramic 1 Tap Hole Basin 850mm
87890 nuie Mayford Compact Cloakroom Cubix 1 Tap Hole Basin 480mm
87904 Hudson Reed Wall Hung Vessel
87905 Hudson Reed Wall Hung Vessel
87936 Hudson Reed Chancery WC Pan
88035 Old London Richmond 560mm Semi Recessed Basin 1 Tap Hole
88045 nuie Carlton Low Level Cistern Ceramic Lever Fittings
88049 Old London Richmond Toilet Pan Close Coupled (Excluding Seat)
88078 Hudson Reed Maya Semi Pedestal
88083 Hudson Reed Arlo 550mm 1 Tap Hole Basin
88143 Old London 600mm Traditional Basin 3 Tap Hole
88506 Furniture Minimalist Slimline Ceramic Basin 1 Tap Hole 500mm
88507 Furniture Minimalist Slimline Ceramic Basin 1 Tap Hole 600mm
88508 Furniture Minimalist Slimline Ceramic Basin 1 Tap Hole 800mm
88510 Furniture Mid-Edge Ceramic Basin 1 Tap Hole 500mm
88511 Furniture Mid-Edge Ceramic Basin 1 Tap Hole 600mm
88514 Furniture Thin-Edge Ceramic Basin 1 Tap Hole 500mm
88515 Furniture Thin-Edge Ceramic Basin 1 Tap Hole 600mm
88517 Furniture Curved Ceramic Basin 1 Tap Hole 500mm
88518 Furniture Curved Ceramic Basin 1 Tap Hole 600mm
88937 Hudson Reed Solar 600mm Polymarble 1 Tap Hole Basin - White
90325 nuie Ceramics Accessories Pneumatic Dual Flush Universal Access Concealed Cistern - Brushed Brass