SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10301, 10313, 10318, 10294, 10297, 10302, 
    10314, 10319, 12552, 12554, 10295, 
    10298, 10303, 10315, 10320, 10299, 
    10304, 10316, 10321, 10300
  )

Query time 0.00073

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 20,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (10301,10313,10318,10294,10297,10302,10314,10319,12552,12554,10295,10298,10303,10315,10320,10299,10304,10316,10321,10300)"
    }
  }
}