下列查询语句怎么进行字段加索引优化查询？

以下几条语句查询时经常用到，要怎么加索引或者给哪些字段加索引会加快查找。谢谢。。。
SELECT
FROM Cmdt
WHERE IS_PATIENT = 0
AND (
STATUS = 'SCHEDULED'
OR STATUS = 'AWAITING'
)
AND END_DATE > NOW()

SELECT
FROM Cmdt
WHERE IS_PATIENT = 0
AND STATUS = 'SCHEDULED'
AND END_DATE > NOW()

SELECT
FROM C_mdt
WHERE STATUS = 'SCHEDULED'
AND RESERVATION_ID = '66'

在你经常用到的字段上设置成索引，http://blog.csdn.net/yuanzhuohang/article/details/6497021

STATUS 字段加索引