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 (
    99003, 99004, 99005, 99006, 99007, 99008, 
    99009, 99010, 99011, 99056, 99057, 
    99058, 99059, 99060, 99061, 99062, 
    99063, 99064, 99065, 99066, 99067, 
    99133, 99141, 99142, 99151, 99152, 
    99169, 99170, 99248, 99257, 99262, 
    99322, 99323, 99324, 99325, 99326, 
    99327, 99328, 99329, 99333, 99334, 
    99335, 99336, 99337, 99338, 99339, 
    99340, 99341
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00125

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "25.94"
    },
    "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": "21.14",
        "eval_cost": "4.80",
        "prefix_cost": "25.94",
        "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 (99003,99004,99005,99006,99007,99008,99009,99010,99011,99056,99057,99058,99059,99060,99061,99062,99063,99064,99065,99066,99067,99133,99141,99142,99151,99152,99169,99170,99248,99257,99262,99322,99323,99324,99325,99326,99327,99328,99329,99333,99334,99335,99336,99337,99338,99339,99340,99341)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
99003
99004
99005
99006
99007
99008
99009
99010
99011
99056
99057
99058
99059
99060
99061
99062
99063
99064
99065
99066
99067
99133
99141
99142
99151
99152
99169
99170
99248
99257
99262
99322
99323
99324
99325
99326
99327
99328
99329
99333
99334
99335
99336
99337
99338
99339
99340
99341