请教关于or语句优化的问题？

请问，or导致了查询效率低下，下面的语句如何优化？

SELECT count(*)
  FROM BU_CONTRACTAPPLICATION BU_Contractapplication
 WHERE ((BU_Contractapplication.FCREATEPSNFID LIKE '/E93A43058AD540C191CEDC9B6C79E940.ogn%') OR
       (EXISTS
        (SELECT EXECUTE_CONCEPT.FMASTERID AS EXECUTE_CONCEPT_fMasterID
            FROM bu_pub_execute EXECUTE_CONCEPT
           WHERE (EXECUTE_CONCEPT.FCREATEPSNID = 'PSN01')
             AND (EXECUTE_CONCEPT.FMASTERID = BU_Contractapplication.fID))))

or 会使索引失效，可尝试使用union代替。
https://blog.csdn.net/woqutechteam/article/details/84522887