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 (
    93392, 93393, 93394, 93395, 93396, 93397, 
    93398, 93399, 93400, 93407, 93408, 
    93409, 93410, 93411, 93412, 93413, 
    93414, 93415, 93416, 93417, 93418, 
    93419, 93420, 93421, 93422, 93423, 
    93424, 93425, 93426, 93427
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00073

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 (93392,93393,93394,93395,93396,93397,93398,93399,93400,93407,93408,93409,93410,93411,93412,93413,93414,93415,93416,93417,93418,93419,93420,93421,93422,93423,93424,93425,93426,93427)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
93392
93393
93394
93395
93396
93397
93398
93399
93400
93407
93408
93409
93410
93411
93412
93413
93414
93415
93416
93417
93418
93419
93420
93421
93422
93423
93424
93425
93426
93427