Joining data from legacy database
You can use ROW_NUMBER (Transact-SQL) to enumerate the rows in BOOKING_PROCCEDURE_TYPE partitioned by BOOKING_ID and ordered by LAST_UPDATE_TIME descending. 

select *
from BOOKING as B
  inner join (
              select *,
                     row_number() over(partition by BOOKING_ID 
                                       order by LAST_UPDATE_TIME desc) as rn
              from BOOKING_PROCCEDURE_TYPE
             ) as BPT
    on B.BOOKING_ID = BPT.BOOKING_ID
where BPT.rn = 1