time complexity without for loop

Question

code:

x=[10,20,30,40,50]       
y=20    
if(y in x):   
  print(x.index(y))   
else:
  print(-1)

Please help me with the below 2 Questions

1. in the above code will the time complexity be O(n)?
2. Is it that for time complexity to be O(n) there has to be a for loop?