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 (
    96088, 96089, 96090, 96091, 96092, 96093, 
    96094, 96095, 96096, 96097, 96098, 
    96099, 96100, 96101, 96102, 96103, 
    96104, 96383, 96384, 96385, 96386, 
    96387, 96388, 96389
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "10.82"
    },
    "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": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "8.42",
        "eval_cost": "2.40",
        "prefix_cost": "10.82",
        "data_read_per_join": "91K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (96088,96089,96090,96091,96092,96093,96094,96095,96096,96097,96098,96099,96100,96101,96102,96103,96104,96383,96384,96385,96386,96387,96388,96389)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
96088
96089
96090
96091
96092
96093
96094
96095
96096
96097
96098
96099
96100
96101
96102
96103
96104
96383
96384
96385
96386
96387
96388
96389