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 (
    94128, 94129, 94130, 94131, 94132, 94133, 
    94134, 94135, 94136, 94137, 94138, 
    94139, 94457, 94484, 94485, 94486, 
    94487, 94488, 94489, 94490, 94491, 
    94492, 94493, 94494, 94495, 94496, 
    94497, 94498, 94499, 94500, 94501, 
    94502, 94503, 94505, 94506, 94507, 
    94508, 94509, 94510, 94511, 94512, 
    94513, 94514, 94515, 94516, 94517, 
    94518, 94519
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00086

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 (94128,94129,94130,94131,94132,94133,94134,94135,94136,94137,94138,94139,94457,94484,94485,94486,94487,94488,94489,94490,94491,94492,94493,94494,94495,94496,94497,94498,94499,94500,94501,94502,94503,94505,94506,94507,94508,94509,94510,94511,94512,94513,94514,94515,94516,94517,94518,94519)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
94128
94129
94130
94131
94132
94133
94134
94135
94136
94137
94138
94139
94457
94484
94485
94486
94487
94488
94489
94490
94491
94492
94493
94494
94495
94496
94497
94498
94499
94500
94501
94502
94503
94505
94506
94507
94508
94509
94510
94511
94512
94513
94514
94515
94516
94517
94518
94519