EF Core performance issue when using dynamic query using Expressions in .Net - linq

Question

Requirement : Select list of records from table for members whose ID and First name matches with records.
The number of members in the request may vary as per the request:
I have written following code to generate dynamic query using expressions.
private Expression<Func<TmpOncMemberAuth, bool>> CreateQueryExpression(List<MemberRequest> memberRequests)
{
var type = typeof(TmpOncMemberAuth);
// member =>
var memberParam = Expression.Parameter(type, "member");
var requests = memberRequests;
Expression selectLeft = null;
Expression filterExpression = null;
foreach (var member in requests)
{
var comparison = BuildSubQuery(member, memberParam, type);
if (selectLeft == null)
{
selectLeft = comparison;
filterExpression = selectLeft;
continue;
}
filterExpression =
Expression.Or(filterExpression, comparison);
}
return Expression.Lambda<Func<TmpOncMemberAuth, bool>>
(filterExpression, memberParam);
}
private Expression BuildSubQuery(MemberRequest member, ParameterExpression memberParam, Type type)
{
// LHS
// member.MemberID
Expression leftMemberID = Expression.Property(memberParam, type.GetProperty("MemberId"));
Expression leftMemberFirstName = Expression.Property(memberParam, type.GetProperty("MemberFirstName"));
// RHS
Expression requestMemberID = Expression.Constant(member.MemberID);
Expression requestFirstName = Expression.Constant(member.FirstName);
// member.MemberID == requestMemberID
Expression compareID =
Expression.Equal(leftMemberID, requestMemberID);
Expression compareFName =
Expression.Equal(leftMemberFirstName, requestFirstName);
// condition for a member
Expression comparison = Expression.AndAlso(compareID, compareFName);
return comparison;
}
// query call in the main
var whereQuery = CreateQueryExpression(memberData);
var memberAuthData = await FindAllAsyncFromTemp(whereQuery);
This generate a SQL query in the below format, which take a lot time
SELECT [#].[CaseID] AS [CaseId], [#].[MemberID] AS [MemberId], [#].[MemberFirstName], [#].[MemberLastName], [#].[MemberDOB]
FROM [#ONCMemberAuth] AS [#]
WHERE ((CASE
WHEN (([#].[MemberID] = '12345') AND ([#].[MemberFirstName] = 'James') ) THEN CAST(1 AS bit)
ELSE CAST(0 AS bit)
END | CASE
WHEN (([#].[MemberID] = '6789') AND ([#].[MemberFirstName] = 'WILLERS') ) THEN CAST(1 AS bit)
ELSE CAST(0 AS bit)
END)
) = CAST(1 AS bit)
I need to create SQL query like below which executes faster than the above one
SELECT [#].[CaseID] AS [CaseId], [#].[MemberID] AS [MemberId], [#].[MemberFirstName], [#].[MemberLastName], [#].[MemberDOB]
FROM [#ONCMemberAuth] AS [#]
WHERE ((([#].[MemberID] = '1234') AND ([#].[MemberFirstName] = 'James')) OR (([#].[MemberID] = '56789') AND ([#].[MemberFirstName] = 'WILLERS') ) )