SP taking 15 minutes, but the same query when executed returns results in 1-2 minutes

This is the footprint of parameter-sniffing. See here for another discussion about it; SQL poor stored procedure execution plan performance - parameter sniffing

There are several possible fixes, including adding WITH RECOMPILE to your stored procedure which works about half the time.

The recommended fix for most situations (though it depends on the structure of your query and sproc) is to NOT use your parameters directly in your queries, but rather store them into local variables and then use those variables in your queries.

its due to parameter sniffing. first of all declare temporary variable and set the incoming variable value to temp variable and use temp variable in whole application here is an example below.

ALTER PROCEDURE [dbo].[Sp_GetAllCustomerRecords]
@customerId INT 
AS
declare @customerIdTemp INT
set @customerIdTemp = @customerId
BEGIN
SELECT * 
FROM   Customers e Where
CustomerId = @customerIdTemp 
End

try this approach

I'd also look into parameter sniffing. Could be the proc needs to handle the parameters slighlty differently.