According to the docs it says to update the settings in /etc/apt/apt.conf.d/20auto-upgrades. So I would update these settings to "0" as well:
APT::Periodic::Update-Package-Lists "0";
APT::Periodic::Unattended-Upgrade "0";
But to be super sure you could still edit /etc/apt/apt.conf.d/10periodic and update the following settings to "0":
APT::Periodic::Update-Package-Lists "0";
APT::Periodic::Download-Upgradeable-Packages "0";
APT::Periodic::AutocleanInterval "0";
Once you have made the updates above none of the packages managed by APT will be automatically updated including MySQL, Apache and PHP.
It's fine to also set APT::Periodic::Update-Package-Lists to "0" as you can still manually update the package lists when you like with sudo apt update and manually update your packages with sudo apt upgrade.
You shouldn't need to make any updates to /etc/apt/apt.conf.d/50unattended-upgrades.
You may also want to disable snap packages from auto-updating however MySQL, Apache and PHP are usually managed by APT so this shouldn't be necessary if you are only really concerned with those packages not being automatically updated.
Important: Disabling automatic updates also means you won't be receiving important security updates for your system so unless you are in the habit of regularly updating your software packages it's probably best to leave automatic updates enabled.
Best Answer
WARNING: Disabling Unattended Upgrades is NOT recommended for most users. Doing so may leave your system vulnerable.
Prerequisite: You need to know how to use a text editor and proper use of sudo before starting. If you are unfamiliar with those, then you really should not be trying to stop Unattended Upgrades yet.
This method won't damage your system.
Open a terminal and carefully edit the following config file:
/etc/apt/apt.conf.d/20auto-upgradesIt looks like this:
Change both "1" to "0". Save and close.
In order to restore Unattended Upgrades, change both "0" back to "1".