By default, MySQL server accounts, with the default authentication plugin, are completely unrelated to system or network users. That means that (again, stress on by default), whenever you run:
CREATE USER you are creating a mysql-only account, no matter if it has the same name than other system (os) or authentication methods.
However, MySQL has available authentication plugins, which you can enable on a per-account basis, and link it, for example, to OS accounts or LDAP/domain network accounts.
I am personally not familiar with Microsoft Authentication methods (I am myself a Linux administrator, so I only familiar with plugins such as unix_socket and PAM) but a quick search tells me that such plugins indeed exist:
I can even see MySQL installed on Linux servers using PAM to authenticate using windows servers:
If you were unsuccessful with trying those, or don't want to pay for them, you could setup an external utility to sync domain users with MySQL local users.