Database Structure...

I am using MySql 3.23.32.
I'm creating an Online Table Reservation System. I've created the following database structure.

1. tbl_Tables (TableCode,otherColumns)
2. tbl_bookings(Bk_id,ccode,BkDate,Bk_From_Time,Bk_To _Time)
3. tbl_bookings_tables(Bk_id,TableCode)

1 contains all the Tables in our Restaurant.
2 contains all the booking details
3 contains TableCode/s which are assigned to a booking.

Users will search the tables by entering their required Date and Time.
Now I could not get the Idea how to get a Table which is available at a particular Date and Time.
Could you please suggest me some idea or New databse structure.
Thanks.
M.Shahzad