Create table SBM_SERVICEBUS_MESSAGE ( SBM_ID int, SBM_MESSAGE_BODY CLOB ) 

INSERT INTO SBM_SERVICEBUS_MESSAGE(sbm_id,SBM_MESSAGE_BODY) VALUES ( 1,'{"CRMId" : "CRM000001"}')

CREATE OR REPLACE PROCEDURE USP_SB_TEST  
AS 
    ls varchar2(4000); 
    ls2 varchar2(4000); 
 
BEGIN 
 
    SELECT CASE WHEN SBM_MESSAGE_BODY IS JSON THEN 1 ELSE 0 END AS IS_JSON,   
           JSON_VALUE(SBM_MESSAGE_BODY, '$.CRMId') AS CRMId 
      INTO ls,ls2 
      FROM SBM_SERVICEBUS_MESSAGE  
     WHERE SBM_ID=1; 
 
    dbms_output.put_line( 'IS JSON=' || ls ); 
    dbms_output.put_line( 'CRMId=' || ls2 ); 
 
END ;