I was testing new Android Run Time (ART), but after that I can't use USB debugging. After that I had changed runtime back do Dalvik and factory reset phone with no success? I also have updated drivers.
I was checking drivers under Computer -> Manage -> Devices but always got message that my drivers are up to date.
Here is solution:
Eclipse -> Android SDK Manager -> Install updates (Google USB Driver)
NOTE: Before you start installation save Eclipse projects and exit Eclipse.