Definitely electrical if it won't release the key. Maybe the charging system went out and you drove the battery flat. Or, if you're saying the lights are BRIGHT... perhaps a run wire or fuse/fusible link like already mentioned

Years ago I took my 2005 hemi in for a TSB PCM update flash, and shortly thereafter it just flat-out quit at one intersection. That was unnerving. That stuff was supposed to fade away with carburetors. When I got it going again, something was scrambled and it was in limp mode with no transmission shifting. I had to cycle it again for it to clear out. I hate electronics