As is ZRH-LUX. 30 mins in the air.
And LUX-FRA is also an international flight, one where - depending on which apron position the aircraft has in LUX an FRA - you will spend more time on the bus to the plane and taxiing, than in the air.

Business class still gets a snack and a drink on either of these. And yes the seats are what SFO777 tends to refer to as "Euro-fraud". Would I book a flight that will take place in December 2018 with LH or LX? Yes I would. Would I book (and pre-pay) on Air Serbia? No bloody way.