The trick in Corfu is not to queue for passport control. Just wait in the seating area at the head of the queue until they come round looking for passengers on that flight towards boarding time. You'll be ushered through to a dedicated booth with the other latecomers. It saves queuing right round the building for ages and is almost risk free (your tolerance for almost risks may vary however).

It's a small airport, but they know what they're doing. Wonderfully Greek check-in staff too, when I was there the bag drop wasn't open and someone asked if it would, receiving a smile, a shrug, and "maybe later... maybe never".