Storage box for cart

[0001]FIG. 1 is a top front perspective view of a storage box for cart showing my new design;

[0002]FIG. 2 is a front view thereof and the rear side view being a mirror image;

[0003]FIG. 3 is a left side view thereof and the right side view being a mirror image;

[0004]FIG. 4 is a top view thereof;

[0005]FIG. 5 is a bottom view thereof; and,

[0006]FIG. 6 is a bottom front perspective view thereof.

[0007]The dash-dash broken lines depict portions of the storage box for cart that form no part of the claimed design.