The ornamental design for a set of keys for a handset, as shown and described.
FIG. 1 is a front perspective view of a set of keys for a handset showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a bottom view;
FIG. 6 is an enlarged front perspective view of the set of keys for a handset shown in FIG. 1;
FIG. 7 is an enlarged front view thereof;
FIG. 8 is an enlarged right side view thereof;
FIG. 9 is an enlarged left side view thereof; and,
FIG. 10 is an enlarged bottom view.
The broken line showing of the remainder of the handset is directed to environment, is for illustrative purposes only, and forms no part of the claimed design.