SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6745aeaf03bbbb79536ad9ecab43b8cb49e86d8f434a5c22911825968d329d07' 
  AND token = 'qUHo7NcuB1Bdl5GRoJe60QgGRIB4w0MoUkJV+4IrIbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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