Seeing as you have such low milage, I assumed this was a new scoot, If it is just low milage ,but, has some age on it, it could mean your caliper (s) are sticking which may have caused over heating, and the warpage. This sticking can be intermitent depending on the weather and how long the scoot sits between rides or seasons. Two things can cause the sticking, corrosion of the caliper pins or pistons. ( or other sliding surfaces).
Both conditions are fixable. If you feel your brakes draging while riding, swerve your bike side to side and if the is any wheel play the movement can force the piston back in to release the brakes. If this doesn't work, a brake service is in order.
If you feel the vibration isn't to bad you might get some miles before the service. Check your pads more often and be careful when it's slippery.