public partial class Transazioni
{
     public int IdVeicolo {get; set}
     public int IdCliente {get; set}
     public int Disabilitato {get; set}
     public long Tipo {get; set}
     ...
}

var context = new DbContext();
var excludeList = new List<int>() {7, 15, 16, 17, 19};
int id_cliente = 100;
var cnt = context.Transazioni.Where(o => o.Id == id_cliente && o.Disabilitato == 0 && !excludeList.Contains(o.Tipo)).Count();

declare @p__linq__0 bigint /*= какое то значение*/
SELECT 
    [GroupBy1].[A1] AS [C1]
    FROM ( SELECT 
        COUNT(1) AS [A1]
        FROM [dbo].[Transazioni] AS [Extent1]
        WHERE ([Extent1].[IdCliente] = @p__linq__0) 
         AND (0 = [Extent1].[Disabilitato]) 
      AND ([Extent1].[IdVeicolo] IS NULL) 
      AND ( NOT (  [Extent1].[Tipo]  IN (7, 15, 16, 17, 18, 19)))
    )  AS [GroupBy1]

declare @p__linq__0 bigint = 1
SELECT 
    [GroupBy1].[A1] AS [C1]
    FROM ( SELECT 
        COUNT(1) AS [A1]
        FROM [dbo].[Transazioni] AS [Extent1]
        WHERE ([Extent1].[IdCliente] = @p__linq__0) 
         AND (0 = [Extent1].[Disabilitato]) 
      AND ([Extent1].[IdVeicolo] IS NULL) 
      AND ( [Extent1].[Tipo] <> 7) 
    )  AS [GroupBy1]
option (recompile)

/*
This query text was retrieved from showplan XML, and may be truncated.
*/

drop table if exists [Transazioni]
create table [Transazioni] (
[Id] bigint,
[IdCliente] bigint, 
[IdVeicolo] bigint,
[Disabilitato] bigint,
[Tipo] bigint,
[Status] bigint,
[StatusFatturazione] bigint
constraint PK primary key clustered ([Id] asc)
)
go
    CREATE NONCLUSTERED INDEX [ix_IdVeicolo_IdCliente_Disabilitato_Tipo_incl] ON [dbo].[Transazioni]
(
	[IdVeicolo] ASC,
	[IdCliente] ASC,
	[Disabilitato] ASC,
	[Tipo] ASC
)
INCLUDE ( 	[Status],
	[StatusFatturazione]) 
    go

create index ix_fltr_IdCliente_incl1
on Transazioni(IdCliente)
include(tipo, IdVeicolo)
where [IdVeicolo] IS NULL and [Disabilitato] = 0
go
update statistics Transazioni with rowcount=82198200
update statistics Transazioni(ix_IdVeicolo_IdCliente_Disabilitato_Tipo_incl) with rowcount=82198200

update statistics Transazioni(ix_fltr_IdCliente_incl1) with rowcount=285439
go

select * from sys.indexes where object_id = object_id('Transazioni')
select * from sys.partitions where object_id = object_id ('Transazioni')

declare @p__linq__0 bigint = 1
SELECT 
    [GroupBy1].[A1] AS [C1]
    FROM ( SELECT 
        COUNT(1) AS [A1]
        FROM [dbo].[Transazioni] AS [Extent1]
        WHERE ([Extent1].[IdCliente] = @p__linq__0) 
         AND (0 = [Extent1].[Disabilitato]) 
      AND ([Extent1].[IdVeicolo] IS NULL) 
      and [Extent1].[Tipo] <> 7
    --  AND ( NOT ( CAST( [Extent1].[Tipo] AS bigint) IN (cast(7 as bigint), cast(15 as bigint), cast(16 as bigint), cast(17 as bigint), cast(18 as bigint), cast(19 as bigint))))
    )  AS [GroupBy1]
    option (recompile)

SELECT 


    [GroupBy1].[A1] AS [C1]
    FROM ( SELECT 
        COUNT(1) AS [A1]
        FROM [dbo].[Transazioni] AS [Extent1] with(index(ix_fltr_IdCliente_incl1))
        WHERE ([Extent1].[IdCliente] = @p__linq__0) 
         AND (0 = [Extent1].[Disabilitato]) 
      AND ([Extent1].[IdVeicolo] IS NULL) 
      AND ( NOT ( CAST( [Extent1].[Tipo] AS bigint) IN (cast(7 as bigint), cast(15 as bigint), cast(16 as bigint), cast(17 as bigint), cast(18 as bigint), cast(19 as bigint))))
    )  AS [GroupBy1]

select @@VERSION

/*
Microsoft SQL Server 2019 (RTM) - 15.0.2000.5 (X64) 
	Sep 24 2019 13:48:23 
	Copyright (C) 2019 Microsoft Corporation
	Express Edition (64-bit) on Windows 10 Pro 10.0 <X64> (Build 19041: ) (Hypervisor)

*/