Retrieving Data From Stored Procedure

Hi,

For a particular application i retrieve records using stored procedure and bind the same to the data grid and display the same. The data are fetched from a table say A joined with couple of tables to staisfy the requirement. Now this table A has around 3700000 + records. The Select statement is as

Select column1, column 2, column 3...................... column 25
from table A

inner join hash table D
on A.Column3 = D.Column3
and A.Column4 = D.Column4
and a.nColumn1 = @ParameterVariable
Inner join table B
on a.nColumn1 =b.nColumn1
inner join table C
on A.column2 = C.column2


Indices defined on A are
IDX1 : Column 3, Column 4
IDX2 : Column 1

Around 350 records per second are inserted into the table A during the peak operation time. During this time when executing the procedure, it takes around 4 mins to fetch just 25000 records.

I need to fine tune the procedure. Please suggest me on same.

Thanks