SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '', 
    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 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    596382, 590365, 590359, 590343, 590337, 
    590566, 590341, 590335, 590366, 590358, 
    589041, 590364, 590369, 590368, 589374, 
    590348, 1070392, 590356, 590351, 590350, 
    589033, 590755, 1070391, 590355, 588389
  ) 
  AND cscart_product_descriptions.lang_code = 'ro'

Query time 0.09017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "29.95"
    },
    "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": 25,
      "rows_produced_per_join": 25,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "27.45",
        "eval_cost": "2.50",
        "prefix_cost": "29.95",
        "data_read_per_join": "95K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "meta_keywords",
        "meta_description",
        "search_words",
        "promo_text"
      ],
      "attached_condition": "((`maniamall_cscart`.`cscart_product_descriptions`.`product_id` in (596382,590365,590359,590343,590337,590566,590341,590335,590366,590358,589041,590364,590369,590368,589374,590348,1070392,590356,590351,590350,589033,590755,1070391,590355,588389)) and (`maniamall_cscart`.`cscart_product_descriptions`.`lang_code` = 'ro'))"
    }
  }
}

Result