SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    298, 53, 232, 55, 337, 205, 3478, 392, 
    66, 69, 5556, 89, 5477, 150, 475, 234, 
    139
  )

Query time 0.00089

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": 17,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (298,53,232,55,337,205,3478,392,66,69,5556,89,5477,150,475,234,139)"
    }
  }
}