There is a test for CoQ10 (it's a blood test) though I have never used it. The laboratory Genova Diagnostics offer an oxidative stress test that includes CoQ10.

I struggle to understand why statins are so widely used. From all the literature I have read, their benefits appear to be minimal. Some people have a condition called hypercholesterolemia that may require cholesterol lowering medication. Most people should be more concerned about their triglyceride levels.