Q: keyboard keys do not work any momentarily

Do you have access to another keyboard you can try?

Keyboard Keys Do Not Respond

Keyboard Doesn’t Work

If those don't work, try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work. The intent is to see if it is specific to one account or a system wide problem. This account can be deleted later.

Isolating an issue by using another user account

If the problem is still there, try booting into the Safe Mode.  Shut down the computer and then power it back up. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the gray Apple icon and a progress bar appear. The boot up is significantly slower than normal. This will reset some caches, forces a directory check, and disables all startup and login items, among other things. If the system operates normally, there may be 3rd party applications which are causing a problem. Try deleting/disabling the third party applications after a restart. For each disable/delete, you will need to restart if you don't do them all at once.

Safe Mode

Safe Mode - About

General information.

Isolating issues in Mac OS X

Troubleshooting Permission Issues

Step by Step to Fix Your Mac

I'd still try another account and the Safe Mode. The Safe Mode resets some things, which may help.

I would try to beg/borrow another keyboard you could attach to see if it was the same.

The only other option I can think of is to take it to an Apple Store or Authorized Apple Repair Center to have someone look at the keyboard.

Genius Bar Reservation

You are welcome.