There is nothing wrong with your CPU usage going high, it won't harm the CPU unless you are having problems keeping it cool. If your CPU is overheating when running at 100%, you have a cooling issue that you need to address.
Your only other options are as said above, turn down graphics settings. Turning on vsync to cap the framerate at 60FPS will also decrease hardware usage. Finally, playing at a higher resolution if possible will shift more load to the graphics card, and should reduce CPU usage a little bit.