SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc72a95439cd70f02398195da78362d7e691b85a36bebb3a2d4d24b850d0f4f6' 
  AND token = '9jmImZyKRwnYV7YOc2FUUdcn/WtBeASXE00TFsT9SII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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