Can actually hinder the user who has already started the form.
Screenreader Forms Key (usually the F key) will take screen reader users to the first field anyway.
If the user isn't watching the screen, they will tab ahead and skip the second field.
If you have to use it, you haven't built the form correctly. Except for limited use of tabindex="0".
Almost any key will interfere with some user agent's default
vs.
Disabled buttons suck - axess lab
Angular techniques: Improve submit button’s UX by NOT disabling it.