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 (
    94354, 94355, 94356, 94357, 94358, 94359, 
    94360, 94361, 94362, 94363, 94364, 
    94365, 94366, 94833, 94834, 94835, 
    94836, 101038, 101039, 101040, 101041, 
    101042, 101043, 101044, 101045, 101046
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "11.72"
    },
    "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": 26,
      "rows_produced_per_join": 26,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "9.12",
        "eval_cost": "2.60",
        "prefix_cost": "11.72",
        "data_read_per_join": "99K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (94354,94355,94356,94357,94358,94359,94360,94361,94362,94363,94364,94365,94366,94833,94834,94835,94836,101038,101039,101040,101041,101042,101043,101044,101045,101046)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}