"Okay." The word is used all the time. It even pops up in some pretty cool artwork (the new "keep calm", perhaps?). Take a look!
1: Everything Will Be Okay... Or Else poster at Life Winning, $18
2: Ralph Steadman's OK Lets Party print at Amazon, $6.80
3: Everything Will Be OK poster at One Horse Shy, $25
4: Always Remember print by Dazey Chic on Etsy, $23