SQL & PL/SQL

Hi all, I have this query:

SELECT ped_num , art1
FROM orders
WHERE hp.order_id = :b2  
    AND at_cat = 'NONE'
    AND status = 'H'
    AND at12 IS NOT NULL
    AND to_date (at12, 'DD-MON-RRRR') <= trunc(to_date(:b1,'ddMONyyyy hh24miss')) ;


SELECT STATEMENT CHOOSE

TABLE ACCESS BY INDEX ROWID ZZ.ORDERS [Analyzed]
   NON-UNIQUE INDEX RANGE SCAN ZZ.ORDERS_N1 [Analyzed]

( 79 distinct values on order_id column )
( 2 distinct values on at_cat column )
( 2 distinct values on status column )
( 1 distinct values on at12 column )

( 93455 records on orders table )

The ORDERS_N1 is non-unique and is on ORDER_ID column.


I don't know if the best is to create an compositive index with all the columns of the query.

Thanks!