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 (
    93303, 93304, 93305, 93306, 93307, 93308, 
    93309, 93310, 93311, 93312, 93313, 
    93314, 93315, 93316, 93317, 93318, 
    93319, 93320, 93321, 93322, 93323, 
    93324, 93325, 93326, 93327, 93328, 
    93329, 93330, 93331, 93332
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00101

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 (93303,93304,93305,93306,93307,93308,93309,93310,93311,93312,93313,93314,93315,93316,93317,93318,93319,93320,93321,93322,93323,93324,93325,93326,93327,93328,93329,93330,93331,93332)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
93303
93304
93305
93306
93307
93308
93309
93310
93311
93312
93313
93314
93315
93316
93317
93318
93319
93320
93321
93322
93323
93324
93325
93326
93327
93328
93329
93330
93331
93332