SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    19938, 19939, 19940, 19941, 19943, 19600, 
    19601, 18570, 14106, 14070, 14045, 
    14051, 14044, 14097, 14093, 14105, 
    14125, 18488, 18489, 18600, 18603
  )

Query time 0.00060

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.03730571,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_products",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "loops": 1,
          "rows": 21,
          "cost": 0.03730571,
          "filtered": 100,
          "attached_condition": "cscart_products.product_id in (19938,19939,19940,19941,19943,19600,19601,18570,14106,14070,14045,14051,14044,14097,14093,14105,14125,18488,18489,18600,18603)"
        }
      }
    ]
  }
}