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 (
    94027, 94028, 94029, 94030, 94031, 94032, 
    94033, 94074, 94075, 94428, 94452, 
    94453, 94454, 94455, 94456, 94458, 
    94459, 94460, 94461, 94462, 94709, 
    94717, 94718, 94719, 94720, 94721, 
    94722, 94723, 94724, 94725
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00078

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (94027,94028,94029,94030,94031,94032,94033,94074,94075,94428,94452,94453,94454,94455,94456,94458,94459,94460,94461,94462,94709,94717,94718,94719,94720,94721,94722,94723,94724,94725)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
94027
94028
94029
94030
94031
94032
94033
94074
94075
94428
94452
94453
94454
94455
94456
94458
94459
94460
94461
94462
94709
94717
94718
94719
94720
94721
94722
94723
94724
94725