2 systems are widely used.
1) lack of any control.
2) The player who has overstayed the time gets 0 points.
But intermediate options are also possible. For example, if you win in 5 minutes, you get a full point. If it takes in 10 minutes - half a point. If 20 minutes, then only a quarter. Etc.
It is interesting whether similar time controls have been used anywhere.
