The question in Korean would be:
잘 지내고 있어요/ 있습니까?
잘 지내고 계십니까?
어떻게 지내세요?
어떻게 지내고 있어요?
Which means " How are you doing? Or " How have you been?" Or " How's it going?"
The response to this question will be:
" 네, 난 (나는/ 저는) 잘 지내(요)/ 잘 지내고 있어(요)" which means " I'm doing good, I'm fine,etc"