Has anyone ever played in the NBA and the NFL and MLB?

No. Although there are a significant number of players who have played in both the NFL and MLB (although only seven since 1970, and none since Drew Henson of the Yankees and Detroit Lions in the 2000s) and 13 who have played in both the NBA and MLB (although none since Mark Hendrickson, who last played in the NBA in 2000 and retired from MLB in 2011), there are only two athletes who have played in both the NBA and NFL, and they both did it in the 1940s, the early days of the NBA: Otto Graham and Bud Grant (both of whom are in the Pro Football Hall of Fame). The links provide lists of athletes who have played in two of the leagues:
https://nbahoopsonline.com/History/Leagues/duelleagues.html
https://en.wikipedia.org/wiki/List_of_athletes_who_played_in_Major_League_Baseball_and_the_National_Football_League

Joe Lillard is probably the closest you can find.

As a professional athlete he was one of the first ten Black men to play in the National Football League. He played during the Great Depression with the Chicago Cardinals, and while there was their legitimate superstar. As a tailback in 1932 and 1933, Lillard was an outstanding rusher, kick returner, and kicker.

Lillard was also a pitcher in Negro league baseball for five seasons from 1932 to 1944, and a guard in basketball for the future Harlem Globetrotters.

https://en.wikipedia.org/wiki/Joe_Lillard
https://aaregistry.org/story/joe-lillard-was-a-stellar-athlete/