Oracle has a query that selects the existing indexes of a table. For example:
SELECT * FROM user_indexes WHERE table_name = \'CM_WCEL\';
But
As per the creation of table, the below tables will have the requested information.
SELECT * FROM user_ind_columns WHERE table_name = 'CM_WCEL';
or
SELECT * FROM dba_ind_columns WHERE table_name = 'CM_WCEL';