For scheduled flights the check in counters are staffed gernerally one hour before departure (Germanwings 1,5 hours); for charter flights they open generally two hours prior to take-off.
When travelling with an etix® - Lufthansa electronic ticket - you can check in and make your seat assignment quickly and easily at home or from work 23 hours before departure. Then simply print out your Online Boarding Pass and go straight to the gate, saving even more time at the airport. If you are travelling with luggage, just bring your bag(s) to one of the designated Lufthansa baggage acceptance counters by the deadline printed on your boarding pass. Lufthansa Online-Check-In