Prices and contracts query The query below is quite slow (taking about half a second). Any obvious things I could improve?

The PRICES table has about 21 million rows and 30 columns while CONTRACTS has 130 k rows and 10 columns.

SELECT
 CONTRACTS.EXT_ID,
 PRICES.REFERENCE_DATE,
 PRICES.PRICE_DATE,
 CONTRACTS.PERIOD,
 PRICES.TIME_TO_MATURITY,
 PRICES.CLOSE_PRICE,
 PRICES.ORIGINAL_PRICE_ID 
FROM
 PRICES INNER JOIN CONTRACTS ON PRICES.CONTRACT_ID = CONTRACTS.ID 
WHERE
 (((CONTRACTS.EXT_ID)=@CONTRACTID)
 AND ((PRICES.REFERENCE_DATE)=@REFDATE)
 AND ((PRICES.STATUS_TYPE) LIKE 'CAL%'));
if you less care about the "Dirty read" then you can use the "(nolock)" after the table name. 
And you already have the indexing.