460W PSU, provided it's good build quality PSU, can handle GTX 1060 GPU just fine. Since GTX 1060 is 150W GPU, add the rest of the system at about 200W and total would be 350W. 460W good quality PSU would be enough for such build.
Some GTX 1060 GPUs do come with 8-pin power connector, e.g MSI GTX 1060 Gaming X 3G which i have in my Skylake build (full specs in my sig).