SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b1913908dc7745dc2bc67556451c334546ef7ea10b08222180eb04c916b28f5' 
  AND token = 'E20BYhMu+uOannZdEMnZfgmiR3xKHfk+rwR7edW1Ht4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}