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 (
    88284, 88280, 88281, 88282, 88276, 88277, 
    88278, 88279, 88275, 88271, 88264, 
    88273
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "5.41"
    },
    "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": 12,
      "rows_produced_per_join": 12,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "4.21",
        "eval_cost": "1.20",
        "prefix_cost": "5.41",
        "data_read_per_join": "45K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (88284,88280,88281,88282,88276,88277,88278,88279,88275,88271,88264,88273)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
88264 nuie Slip Resistant Rectangular Slimline Shower Tray 1200 x 700mm - White
88271 nuie Slip Resistant Rectangular Slimline Shower Tray 1100 x 900mm - White
88273 nuie Slip Resistant Rectangular Slimline Shower Tray 1200 x 760mm - White
88275 nuie Slip Resistant Rectangular Slimline Shower Tray 1200 x 900mm - White
88276 nuie Slip Resistant Rectangular Slimline Shower Tray 1300 x 800mm - White
88277 nuie Slip Resistant Rectangular Slimline Shower Tray 1400 x 700mm - White
88278 nuie Slip Resistant Rectangular Slimline Shower Tray 1400 x 760mm - White
88279 nuie Slip Resistant Rectangular Slimline Shower Tray 1400 x 800mm - White
88280 nuie Slip Resistant Rectangular Slimline Shower Tray 1400 x 900mm - White
88281 nuie Slip Resistant Rectangular Slimline Shower Tray 1500 x 700mm - White
88282 nuie Slip Resistant Rectangular Slimline Shower Tray 1500 x 760mm - White
88284 nuie Slip Resistant Rectangular Slimline Shower Tray 1500 x 900mm - White