Magento 2 has a weird bug, where the admin account gets locked in and never gets unlocked, even if in the database the lock expires timer is done. We were working on a client's website and even after doing everything, it did not get fixed, so the only option left for you is creating a new admin user.
Even if you unlock the admin user in the SSH, it still wont work. I have already tried and it did not work. I created an admin user from the SSH and it instantly started working with the new ID which I created.
So, here is how to do it. You need to login to SSH console and goto your magento root folder. Then run this command :
php bin/magento admin:user:create --admin-user='newadmin' --admin-password='admin123' --email@example.com' --admin-firstname='Jon' --admin-lastname='Doe'
Now go ahead and login to your admin panel and login with this new username and password of :
username - newadmin
password - admin123