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, 
  cscart_product_descriptions.meta_keywords, 
  cscart_product_descriptions.meta_description, 
  cscart_product_descriptions.search_words, 
  cscart_product_descriptions.promo_text, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    1154, 3315, 3318, 3687, 5076, 4691, 3071, 
    513, 3505, 3319, 3306, 3296, 1172, 1173, 
    4917, 4918, 3430, 3429, 3437, 3436, 
    3438, 3500, 3501, 3431
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00064

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "28.91"
    },
    "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": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "index_condition": "((`gaseus`.`cscart_product_descriptions`.`product_id` in (1154,3315,3318,3687,5076,4691,3071,513,3505,3319,3306,3296,1172,1173,4917,4918,3430,3429,3437,3436,3438,3500,3501,3431)) and (`gaseus`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "26.51",
        "eval_cost": "2.40",
        "prefix_cost": "28.91",
        "data_read_per_join": "109K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "meta_keywords",
        "meta_description",
        "search_words",
        "promo_text",
        "unit_name"
      ]
    }
  }
}