A more proper naming would be:
Futurama - S07E05.mp4
Also even if there is only one season "Season folders are a good idea.
This is a basic map as to how Plex likes TV shows in general.
TV Shows ← The TV library points here
_______ShowName (year)
____________Season 01
__________________ShowName (year) - s01e01 - Optional Name.ext
__________________ShowName (year) - s01e02 - Optional Name.ext
__________________and so on for the shows in season 01
____________Season 02 ← just like Season 01
____________Season 03 ← and so on for each season
____________Season 00 ← or “Specials”
__________________ShowName (year) - s00e01 - Optional name
__________________ShowName (year) - s00e02 - Optional name
__________________and so on for each special
Note 1: the eXX part of the specials must match EXACTLY what is found in TheTVDB
Note 2: The (year) may be omitted for shows that do not have more than one occurrence throughout the years.
There are many other structures and naming systems that work but this is the one I use and it just works.
For a mass rename I use FileBot with this format string {n.replaceTrailingBrackets()} - {s00e00.lower()} - {t}