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 (
    12684, 12714, 13260, 13267, 13176, 13162, 
    13169, 13232, 13225, 13190, 13183, 
    13239, 13204, 13197, 13246, 13218, 
    13211, 13253, 13302, 13303, 13308, 
    13309, 13306, 13307, 13310, 13311, 
    13312, 13313, 13304, 13305, 12349, 
    12364, 12259, 12504, 12524, 12379, 
    13319, 1154, 3315, 6843, 3318, 3687, 
    5076, 6840, 4691, 3071, 513, 3505
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00174

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "48.49"
    },
    "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": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "index_condition": "((`test2_gaseus`.`cscart_product_descriptions`.`product_id` in (12684,12714,13260,13267,13176,13162,13169,13232,13225,13190,13183,13239,13204,13197,13246,13218,13211,13253,13302,13303,13308,13309,13306,13307,13310,13311,13312,13313,13304,13305,12349,12364,12259,12504,12524,12379,13319,1154,3315,6843,3318,3687,5076,6840,4691,3071,513,3505)) and (`test2_gaseus`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "43.69",
        "eval_cost": "4.80",
        "prefix_cost": "48.49",
        "data_read_per_join": "219K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "meta_keywords",
        "meta_description",
        "search_words",
        "promo_text",
        "unit_name"
      ]
    }
  }
}