SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1609, 1610, 1638, 1689, 1693, 1864, 1939, 
    2202, 2361, 2387, 2394, 2396
  )

Query time 0.00158

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": 12,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (1609,1610,1638,1689,1693,1864,1939,2202,2361,2387,2394,2396)"
    }
  }
}