You mean you enabled Fast Boot in the BIOS and as a result the BIOS doesn't see the keyboard or mouse? If this is the case, just turn off Fast Boot. In modern PCs, this feature doesn't speed up the boot process enough to make it worthwhile to put up with the inconveniences that it causes.
Or are you talking about Windows 10 FastBoot? To disable the Windows 10 FastBoot feature,
- Navigate to Settings / System / Power & Sleep / Additional Power Settings.
- Select Choose what the power buttons do.
- Select Change settings that are currently unavailable.
- Uncheck Turn on fast startup.
- Select Save changes.
Hope this helps,