Performance optimization of critical functions SQL queries

As query.getStateAndStatus_MAIN* is used to know the state and state of BP across different workflows which is common use case for many clients across the industry. On a high volume application environment this query is taking more than 10+ mins and causing database CPU increase and impacting overall processing time.

Oracle vendor recommended to optimize this query.  

Similar to above, below is another query which is captured in AWR report each time during application slowness.

SELECT MSG.MESSAGE_NAME AS MESSAGENAME, MSG.MESSAGE_ID, CREATED_DATETIME, MESSAGE_SIZE, MSG.CONTENT_TYPE , EXTRACTABLE_UNTIL, 0 AS EXTRACTABLE_COUNT, 0 AS EXTRACTABLE, 2 AS EXTRACT_TYPE FROM MBX_MESSAGE MSG, MBX_MAILBOX MBX, DOCUMENT, MBX_EXTRACT_TIL TIL WHERE MSG.MAILBOX_ID = MBX.MAILBOX_ID AND MSG.DOC_ID = DOCUMENT.DOC_ID AND (MBX.PATH = :1 )AND MSG.MESSAGE_NAME_UP LIKE :2 AND MSG.MESSAGE_ID = TIL.MESSAGE_ID UNION ALL SELECT MSG.MESSAGE_NAME AS MESSAGENAME, MSG.MESSAGE_ID, CREATED_DATETIME, MESSAGE_SIZE, MSG.CONTENT_TYPE , TO_DATE ('1900-01-01', 'YYYY-MM-DD') AS EXTRACTABLE_UNTIL, EXTRACTABLE_COUNT, 0 AS EXTRACTABLE, 0 AS EXTRACT_TYPE FROM MBX_MESSAGE MSG, MBX_MAILBOX MBX, DOCUMENT, MBX_EXTRACT_COUNT CNT WHERE MSG.MAILBOX_ID = MBX.MAILBOX_ID AND MSG.DOC_ID = DOCUMENT.DOC_ID AND (MBX.PATH = :3 )AND MSG.MESSAGE_NAME_UP LIKE :4 AND MSG.MESSAGE_ID = CNT.MESSAGE_ID UNION ALL SELECT MSG.MESSAGE_NAME AS MESSAGENAME, MSG.MESSAGE_ID, CREATED_DATETIME, MESSAGE_SIZE, MSG.CONTENT_TYPE , TO_DATE ('1900-01-01', 'YYYY-MM-DD') AS EXTRACTABLE_UNTIL, 0 AS EXTRACTABLE_COUNT, EXTRACTABLE, 1 AS EXTRACT_TYPE FROM MBX_MESSAGE MSG, MBX_MAILBOX MBX, DOCUMENT, MBX_EXTRACTABLE EXT WHERE MSG.MAILBOX_ID = MBX.MAILBOX_ID AND MSG.DOC_ID = DOCUMENT.DOC_ID AND (MBX.PATH = :5 )AND MSG.MESSAGE_NAME_UP LIKE :6 AND MSG.MESSAGE_ID = EXT.MESSAGE_ID

Please help to optimize these queries which will in turn help lot of Sterling B2B users and improve application stability.