Are there any Boeing 747 still flying for commercial use?
Quite a few, actually.

British Airways is the largest operator of B747-400 and flies a number of routes:


  Where does the Boeing 747-400 fly?
  
  The aircraft operates on a variety of routes, including:
  
  Beijing  Boston Cape Town Dubai Lagos 
  
  Las Vegas Mexico Miami New York (JFK) 
  
  Phoenix San Francisco Toronto 


Air China operates both 747-400s and 747-8s

KLM does so but is phasing the 747-400 out

Korean Air, Lufthansa, Thai Airways, Virgin, El Al, Saudia operate 747s, among others.

Wikipedia lists 489 747s in service as of July 2017 though around half of them are cargo and the numbers would have reduced still further by now.

The latest data that I could lay my hands on lists the following airlines (less than twenty, sadly):


  
  Air China
  Air India
  Asiana Airlines
  Atlas Air
  British Airways
  China Airlines
  Corsair
  El Al
  Iraqi Airways
  KLM Royal Dutch Airlines
  Korean Air
  Lufthansa
  Mahan Air
  Qantas
  Rossiya Airlines
  Thai Airways
  Virgin Atlantic
  Wamos Air