SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1800, 1804, 1803, 1221, 1224, 1762, 408
  )

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": 7,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (1800,1804,1803,1221,1224,1762,408)"
    }
  }
}