There is a new security feature of user's account locking in MySQL 5.7. Administrators can lock and unlock accounts for better control over who can log in.
I need the exact command to Lock / unlock the user's account.
From the MySQL Documentation, I got the answer, there is very simple command to LOCK and UNLOCK MySQL user:
ALTER USER 'jeffrey'@'localhost' ACCOUNT LOCK;
ALTER USER 'jeffrey'@'localhost' ACCOUNT UNLOCK;