I personally feel this is slightly incorrect.
Three little words 'are you okay?' Will not do anything on their own.
Asking these everyday will eventually crack the persons hard exterior, and even asking them once but followed by 'I know your not', is what can make the difference.
Please if you feel like someone's not okay, don't leave it at that question, as much as it may hurt for both them and you, keep pushing cause it may help.