MacBook Pro keyboard issue

You do not say what exact Mac /model /year /size /retina /touchbar is this

or

what exact macOS you are currently running?

see if you qualify: https://support.apple.com/keyboard-service-program-for-mac-notebooks

You can try rebooting, you can Try resetting NVRAM/PRAM http://support.apple.com/kb/ht1379

If the issue continues you can trouble shoot further:

Try a SafeBoot https://support.apple.com/en-us/HT201262

Takes noticeable longer to get to the login screen, does a 5-15 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc.

This test will tell you if third party interference; extensions etc are not loaded in safe boot mode.

Test issue in another user (or guest user) account  https://support.apple.com/en-us/HT204443

This will tell you if it a universal issue or isolated to your user/admin account. 

In or out of warranty you can get a free over the counter 'Apple Service Diagnostics' test /assessment

Make an appointment for a "hardware issue"—

https://www.apple.com/retail/geniusbar/