the card at low fan speed should be in the 40-50c range with no load on the card. with a game load is should stay in the 60-70c range. if it going higher check that the fan is not full of dust. the last isue would be dried out thermal paste or a bad fan.
Definetly not optimal, but it isnt dangerous either, if you reach 90ºC, then you have a problem.
Download GPU-Z and look at the clocks and fans rpms, maybe even change the thermal paste.