If I remember correctly, either Superboy or Luthor Prime or possibly both were introduced a few years before Crisis on Infinite Earths. I believe it was in DC Comics Presents. Back then Prime Earth was supposed to be our Earth.
Actually, neither character made their appearance before the
Crisis (well, there actually was no Luthor Prime. Are you thinking of Alexander Luthor, Alex Luthor's father, the only hero on Earth-3? I can't find a record of his first appearance, unless it was in
Crisis on Infinite Earths #1).
Superboy Prime made his debut in
DC Comics Presents #87, which was dated November 1985.
CoIE began in April 1985.
Actually, on another tangent, there were a bunch of titles that spun off from Infinite Crisis, most of which did not even survive more than a couple of years and have already long been canceled. Isn't Blue Beetle the only one of these still being published?
Sadly,
Blue Beetle was canceled earlier this year at issue #36. It is now the second feature in
Booster Gold.
And, I guess it depends on what you view as a title spun off from
Infinite Crisis, as several titles were, such as
Wonder Woman,
Justice League of America, and a little later on,
Justice Society of America. All three of those titles are still on-going.
Flash: Fasted Man Alive restarted similar to those titles, but after Bart's death, the numbering reverted to Wally's run. Either way, the title is now canceled, awaiting a new
Flash #1, presumably with Barry, though nothing's been revealed yet.
As far as the new characters/teams launched in the wake of
Infinite Crisis, yes, I do think they are all now canceled.
Checkmate lasted 30 odd issues (though only the first 25, Rucka and later Rucka/Trautmann penned issues are worthwhile),
Shadowpact ran for 25 issues, as did
The All New Atom.
The other series, like
Freedom Fighters and
OMAC were mini-series.
