SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  cscart_product_descriptions.full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    7985, 7986, 8040, 9545, 13134, 13136, 
    13146, 15999, 16000, 16001, 19743, 
    19745, 19746, 19747, 19749, 19750, 
    19751, 19752, 19753, 19754, 29970, 
    29971, 64687, 69464
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00108

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.15"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id",
        "idx_product_desc_lang",
        "idx_product_name_search",
        "idx_product_desc_sort"
      ],
      "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",
      "cost_info": {
        "read_cost": "18.76",
        "eval_cost": "2.40",
        "prefix_cost": "21.16",
        "data_read_per_join": "109K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`cscart_db`.`cscart_product_descriptions`.`product_id` in (7985,7986,8040,9545,13134,13136,13146,15999,16000,16001,19743,19745,19746,19747,19749,19750,19751,19752,19753,19754,29970,29971,64687,69464)) and (`cscart_db`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}