Well, the device is detected in ADB only, you probably haven't installed [fastboot][1] drivers. `< waiting for any device >` means that the computer is waiting for a device in fastboot mode. 

Download the drivers from [this page][2] then install. `fastboot oem unlock` should work now.

[Learn][3] the difference between these two protocols (ADB and Fastboot).

This [question][4] may also help.


  [1]: https://www.androidcentral.com/android-z-what-fastboot
  [2]: https://developer.android.com/studio/run/win-usb.html
  [3]: https://bbs.elephone.hk/thread-3683-1-1.html#.WqMbl3njKUk
  [4]: https://android.stackexchange.com/questions/58187/adb-can-discover-devices-but-not-fastboot