The greater than operator causing performance issue

The below query execution is taking long time. Is there any way to increase the performance without modifying the logic. We have observed another thing that, when we replace '>' with '='  it's executing very quickly.

Query cost with '>' operator

     SELECT STATEMENT  ALL_ROWSCost: 2,758,228  Bytes: 224,636,855  Cardinality: 722,305

Query cost with '=' operator

     SELECT STATEMENT  ALL_ROWSCost: 2,758,228  Bytes: 311  Cardinality: 1

Oracle Database Ver: 12C

SELECT  *

  FROM  custom_table cust_tab

WHERE  1 = 1

    AND ( SELECT  Count( * )

            FROM  custom_view cust_v

           WHERE  ( cust_tab.Customer_number    = cust_v.Coulm1

                    OR cust_tab.Customer_number = cust_v.Coulm2

                    OR cust_tab.Customer_number = cust_v.Coulm3