Data listed on dark web is for an old, inaccessible email address: should I worry?

Through Lifelock, I received an email alert that my data was detected on the dark web. Normally I would change my password, but this alert is for an email address that is no longer accessible (my own freelance business name.com). What can I do in this case besides worry? And is worry even required? Before I deactivated my personal site I changed my account information to my current email address on every site I had used it. Other than a couple of sites I couldn't access to change, and probably a few I don't remember being on, this email address has been "gone" for over five years. Can this old email address still get me in trouble?