Lock_time in mysql slow log

   ----- start_utime
 l    .
 o    .
 c   lock tables
 k    .
 t    .
   ----- utime_after_lock
 q    .
 u    .
 e   query execution
 r    .
 y    .
 t    .
    ------ end_query_time = current_time
 
lockt= utime_after_lock - start_utime
queryt= current_time - utime_after_lock