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 (
    95466, 95467, 95468, 95469, 95470, 95471, 
    95472, 95473, 95474, 95475, 95476, 
    95477, 95478, 95479, 95480, 95481, 
    95482, 95483, 95484, 95485, 95486, 
    95487, 95494, 95495, 95496, 95504, 
    95505, 95506, 95507, 95508
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00089

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 (95466,95467,95468,95469,95470,95471,95472,95473,95474,95475,95476,95477,95478,95479,95480,95481,95482,95483,95484,95485,95486,95487,95494,95495,95496,95504,95505,95506,95507,95508)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95466
95467
95468
95469
95470
95471
95472
95473
95474
95475
95476
95477
95478
95479
95480
95481
95482
95483
95484
95485
95486
95487
95494
95495
95496
95504
95505
95506
95507
95508