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 (
    97994, 97995, 97996, 97997, 97998, 97999, 
    98000, 98024, 98025, 98026, 98027, 
    98028, 98029, 98457, 98458, 98459, 
    98460, 98461, 98462, 98463, 98464, 
    98465, 98466, 98467, 98468, 98469, 
    98470, 98471, 98472, 98473, 98474, 
    98475, 98496, 98497, 98498, 98499, 
    98500, 98501, 98515, 98521, 98522, 
    99026, 99027, 99028, 99029, 99030, 
    99031, 99032
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00112

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 (97994,97995,97996,97997,97998,97999,98000,98024,98025,98026,98027,98028,98029,98457,98458,98459,98460,98461,98462,98463,98464,98465,98466,98467,98468,98469,98470,98471,98472,98473,98474,98475,98496,98497,98498,98499,98500,98501,98515,98521,98522,99026,99027,99028,99029,99030,99031,99032)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
97994
97995
97996
97997
97998
97999
98000
98024
98025
98026
98027
98028
98029
98457
98458
98459
98460
98461
98462
98463
98464
98465
98466
98467
98468
98469
98470
98471
98472
98473
98474
98475
98496
98497
98498
98499
98500
98501
98515
98521
98522
99026
99027
99028
99029
99030
99031
99032