The ban means he will miss the rest of Slavia's Europa League campaign and the Czech Republic's games at the European Championship.
Valencia left the field after Mouctar Diakhaby said he was insulted by Cádiz defender Juan Cala, who denied the claim.
It comes after a recent mass shooting spree at Asian-owned spas in the state of Georgia.
The US President and Vice-President denounced racism hidden 'in plain sight' as they visited Atlanta, days after a white gunman killed eight people, mostly Asian American women.
Breonna Taylor was killed by police during a raid on her apartment last year. Her death sparked protests against police abuses and racism in the US.
It comes after Manchester United's Axel Tuanzebe and Lauren James became the latest players to be targeted by online abusers.
The man died after being beaten by supermarket security on the eve of Brazil's annual Black Consciousness Day, sparking angry protests at Carrefour shops across the country.
Greg Clarke, also a vice president of FIFA, was also accused of inappropriate terms in reference to South Asian and gay players.