PHP should automatically disconnect after MySQL, but it is blocked with Get_lock?

Visit localhost/ci
The code is as follows (it's a lock)

When it's done,
I used navicat to establish a connection, tune command line, lock, and found blocked:

Why is it? The connection to PHP should be released.
Ps:
Environment for Windows+nginx+php+mysql

Reply content:

Visit localhost/ci
The code is as follows (it's a lock)

When it's done,
I used navicat to establish a connection, tune command line, lock, and found blocked:

Why is it? The connection to PHP should be released.
Ps:
Environment for Windows+nginx+php+mysql

Unlock it after you lock it.

unlock tables

Or

rollback

select release_lock('lock1');

Release lock

