How to get Record faster from large Volume Data? In Oracle

Hi  To All,

                   I Had a situation get the Customer Record so fast .I have using  Asp.net and and Back End Oracle.My desire is get the customer Record according to the customer phone..I had two PhoneNo Column ,,,When i search single mobile no its give the record fastly.if i check the Cell_No  number for the search its getting lot more time to fetch the record Provide me the Right solution for this issue.

Table structure :

              cust_Details  :

 

                     Phone_No           numeric  

                     Cell_NO              Numeric     

                     Adress                 Varchar2(50)

  

                         

 

 

query  1:     select * from view1 where Phone_No=9943540365   Faster One

 

                   

 

query 2:      select * from view1  where  Cell_NO=9962840365   Slower One

 

 

 

   Thanks in advance

 

 

 

 

  Karthik.k