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 (
    94975, 94976, 94977, 94978, 94979, 94980, 
    94981, 94982, 94983, 94984, 94985, 
    94986, 94987, 94988, 94989, 94990, 
    94991, 94992, 94993, 94994, 94995, 
    94996, 94997, 94998, 94999, 95000, 
    95001, 95002, 95003, 95004
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00080

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 (94975,94976,94977,94978,94979,94980,94981,94982,94983,94984,94985,94986,94987,94988,94989,94990,94991,94992,94993,94994,94995,94996,94997,94998,94999,95000,95001,95002,95003,95004)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
94975
94976
94977
94978
94979
94980
94981
94982
94983
94984
94985
94986
94987
94988
94989
94990
94991
94992
94993
94994
94995
94996
94997
94998
94999
95000
95001
95002
95003
95004