They has a layover with Scandinavian Airlines, arriving in Copenhagen at 10:10 AM and departing for Athens at 15:55 PM the same day.
They are considering leaving the airport during the 5 hours and 45 minutes layover to explore Copenhagen briefly and have lunch.
They are unsure whether this is enough time, taking into account immigration, security, and reboarding procedures, and are asking if the layover duration is too tight for leaving the airport safely.