SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7da29589856b117cae092d04615ab7899fd3dc8a227c7f162a1e1bea2161f4ca' 
  AND token = '7UdJqzTyjBZJs5auhoruzVNrd2N7cRlMP9eEbhmrphU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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