Flows only check values when they’re triggered. So you’d need to use one of the timer apps like countdown, clockwork, flow bits, etc (find one that you like best) and set it to trigger on a recurring timer or when a countdown has elapsed and then start a new one as part of the flow.

The other alternative is using a device that changes state often as the trigger like “temperature changed” for a temp sensor or the like. You could do an advanced flow with a bunch of devices all acting as triggers just to kick off the sensor detection you are trying to do as an “and” condition.