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 (
    97868, 97869, 97870, 97871, 97872, 97873, 
    97874, 97875, 97876, 97877, 97878, 
    97879, 97880, 97881, 97882, 97883, 
    97884, 97885, 97886, 97887, 97888, 
    97889, 97890, 97891, 97892, 97893, 
    97894, 97895, 97896, 97897, 97898, 
    97899, 97900, 97901, 97902, 97903, 
    97904, 97905, 97906, 97907, 97908, 
    97909, 97910, 97911, 97912, 97913, 
    97914, 97915
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00084

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "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 (97868,97869,97870,97871,97872,97873,97874,97875,97876,97877,97878,97879,97880,97881,97882,97883,97884,97885,97886,97887,97888,97889,97890,97891,97892,97893,97894,97895,97896,97897,97898,97899,97900,97901,97902,97903,97904,97905,97906,97907,97908,97909,97910,97911,97912,97913,97914,97915)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}