A similar symbol was used in ancient Egypt: five lines radiating from a common point. Regular arrays of them on a dark blue background covers some ceilings including some in the Festival Hall of Thutmoses III at Karnak. I'm not an egyptologist, so I can't say that they are as old as the building, but if they are, that would be about 1450BC.

You might actually be interested in the /r/AskScience angle on pointy stars here. The tl;dr is that for those of us with imperfect vision stars can appear to have points, called diffraction spikes, when viewed without corrective lenses.