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 (
    93321, 93322, 93323, 93324, 93325, 93326, 
    93327, 93328, 93329, 93330, 93331, 
    93332, 93333, 93334, 93335, 93336, 
    93337, 93356, 93357, 93358, 93868, 
    93869, 93870, 93871, 93896, 93897, 
    93898, 93899, 93900, 93901, 93902, 
    93903, 93904, 93905, 93906, 93907, 
    93908, 93909, 93910, 93911, 93912, 
    93913, 93914, 93915, 93916, 93917, 
    93918, 93919
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00097

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 (93321,93322,93323,93324,93325,93326,93327,93328,93329,93330,93331,93332,93333,93334,93335,93336,93337,93356,93357,93358,93868,93869,93870,93871,93896,93897,93898,93899,93900,93901,93902,93903,93904,93905,93906,93907,93908,93909,93910,93911,93912,93913,93914,93915,93916,93917,93918,93919)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
93321
93322
93323
93324
93325
93326
93327
93328
93329
93330
93331
93332
93333
93334
93335
93336
93337
93356
93357
93358
93868
93869
93870
93871
93896
93897
93898
93899
93900
93901
93902
93903
93904
93905
93906
93907
93908
93909
93910
93911
93912
93913
93914
93915
93916
93917
93918
93919