Can leg claudication affect my sexual performance?

Depends. On whether you use your legs during sex. Certainly, blockage of the arteries to the legs can be associated with blockage of the arteries to the penis. Viagra (sildenafil) and similar drugs dilate these arteries compensating for partial blockage allowing for erection.
No. Claudication of the leg in and of itself would not cause sexual dysfunction but poor blood supply to the leg can be associated with poor blood flow to the sexual organs.