I claim the ornamental design for a flute key pendant, as shown and described.
FIG. 1 is a perspective view of a flute key pendant, showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left-side elevational view thereof, the right-side elevational view being a mirror image thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The broken lines showing a necklace in FIG. 1, a loop in FIGS. 1-5, and engravings on a front flute key in FIGS. 1 and 2 depict environmental matter and form no part of the claimed design. The broken lines shown in FIG. 3 represent portions of the flute key pendant which form no part of the claimed design.