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 (
    480519, 596382, 697795, 1108774, 386215, 
    589116, 1732209, 590365, 589122, 611344, 
    524885, 590294, 590359, 503738, 611343, 
    1114057, 611248, 1108257, 1232917, 
    589813, 697874, 592084, 612918, 592827, 
    1232953, 589079, 697492, 1233035, 
    594419, 1108259, 696364, 588450
  ) 
  AND cscart_product_descriptions.lang_code = 'ro'

Query time 0.00521

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "38.38"
    },
    "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": 32,
      "rows_produced_per_join": 32,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "35.18",
        "eval_cost": "3.20",
        "prefix_cost": "38.38",
        "data_read_per_join": "122K"
      },
      "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 (480519,596382,697795,1108774,386215,589116,1732209,590365,589122,611344,524885,590294,590359,503738,611343,1114057,611248,1108257,1232917,589813,697874,592084,612918,592827,1232953,589079,697492,1233035,594419,1108259,696364,588450)) and (`maniamall_cscart`.`cscart_product_descriptions`.`lang_code` = 'ro'))"
    }
  }
}

Result