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 (
    95369, 95370, 95371, 95372, 95373, 95374, 
    95375, 95377, 95378, 95379, 95380, 
    95381, 95382, 95383, 95384, 95385, 
    95386, 95387, 95388, 95389, 95390, 
    95391, 95392, 95393, 95402, 95403, 
    95404, 95405, 95406, 95407
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00043

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 (95369,95370,95371,95372,95373,95374,95375,95377,95378,95379,95380,95381,95382,95383,95384,95385,95386,95387,95388,95389,95390,95391,95392,95393,95402,95403,95404,95405,95406,95407)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95369
95370
95371
95372
95373
95374
95375
95377
95378
95379
95380
95381
95382
95383
95384
95385
95386
95387
95388
95389
95390
95391
95392
95393
95402
95403
95404
95405
95406
95407