Private Sub Кнопка0_Click()
  Dim rs As DAO.Recordset
  Dim t As Long
  Debug.Print  "Последовательно" 
  Debug.Print CDbl(Now)
  Set rs = CurrentDb.OpenRecordset( "Select * from t where t.fio="  "Иванов"  ";" )
  rs.MoveLast ' Ждем, пока выполнится весь запрос
  For t =  1  To  100000000 
    t = t
  Next
  Debug.Print CDbl(Now)
  Debug.Print " ---------------------------"
 
End Sub

Private Sub Кнопка1_Click()
  Dim rs As DAO.Recordset
  Dim t As Long
  Debug.Print  "Параллельно" 
  Debug.Print CDbl(Now)
  Set rs = CurrentDb.OpenRecordset( "Select * from t where t.fio="  "Иванов"  ";" , , dbRunAsync) 
  ' На самом деле последний аргумент не нужен
  For t = 1 To 100000000
    t = t
  Next
  rs.MoveLast ' Подождем, если еще не закончилось... 
  Debug.Print CDbl(Now)
  Debug.Print " ---------------------------"
 
End Sub

Последовательно  Параллельно
 37877 , 958600       37877 , 958773    (начало)
 37877 , 958704       37877 , 958854    (завершение)
 ---
 
     0 , 000104           0 , 000081    (разница)

Dim t As Double, t1 As Double

Private Sub Form_Open(Cancel As Integer)
  t = Time
  Debug.Print  "Не мешаем загружать записи" 
  Me.TimerInterval =  1000  ' Секунда
End Sub

Private Sub Form_Timer()
  t1 = t
  t = Time
  Debug.Print mSec(t, t1) &  " мс: "  & Me.Recordset.RecordCount
End Sub

Private Function mSec(a As Double, b As Double)
  mSec = (a - b) *  24  *  60  *  60  *  1000 
End Function

Private Sub Form_Open(Cancel As Integer)
  Dim t As Long
  Debug.Print  "Мешаем загружать записи" 
  Do While True
    t = t +  1 
    If (t Mod  100000 ) =  0  Then
      Debug.Print Me.Recordset.RecordCount
    End If
  Loop
End Sub

Не мешаем загружать записи
 999 , 999999996959  мс:  501 
 1000 , 00000000655  мс:  501 
 999 , 999999996959  мс:  501 
 1000 , 00000000655  мс:  501 
...
...
 А после нажатия на кнопку перехода к последней записи:
 1000 , 00000000655  мс:  2293760 
 999 , 999999996959  мс:  2293760 
...

Private Sub Кнопка3_Click()
  Dim t As Long
  Dim rs As DAO.Recordset
  Debug.Print  "Мешаем рекордсету" 
  Set rs = CurrentDb.OpenRecordset( "Select * from t WHERE t.fio="  "Иванов"  ";" )
  For t =  1  To  100000000 
    t = t
    If (t Mod  100000 ) =  0  Then
      Debug.Print rs.RecordCount
    End If
  Next
  Debug.Print " ---------------------------"
 
End Sub

Мешаем рекордсету
  1  
  1  
  1  
  1  
...

  Dim tt As Double
  Dim tt1 As Double
  Dim rs As DAO.Recordset
  Dim rs1 As DAO.Recordset
  
  tt1 = Timer
  Set rs = CurrentDb.OpenRecordset( "Select * from t WHERE t.fio="  "Иванов"  ";" , , dbRunAsync)
  Set rs1 = CurrentDb.OpenRecordset( "Select * from t1 WHERE t1.fio="  "Иванов"  ";" , , dbRunAsync)
  tt = Timer
  Debug.Print mSec(tt, tt1) &  " мс. Rs: "  & rs.RecordCount &  " rs1 "  & rs1.RecordCount
  rs.MoveLast
  tt1 = tt: tt = Timer
  Debug.Print mSec(tt, tt1) &  " мс. Rs: "  & rs.RecordCount &  " rs1 "  & rs1.RecordCount
  rs1.MoveLast
  tt1 = tt: tt = Timer
  Debug.Print mSec(tt, tt1) &  " мс. Rs: "  & rs.RecordCount &  " rs1 "  & rs1.RecordCount
  Debug.Print  "---------------------------" 

  Dim t As Long
  Dim tt As Double
  Dim tt1 As Double
  Dim rs As DAO.Recordset
  Dim rs1 As DAO.Recordset
  
  tt1 = Timer
  Set rs = CurrentDb.OpenRecordset( "Select * from t WHERE t.fio="  "Иванов"  ";" , , dbRunAsync)
  Set rs1 = CurrentDb.OpenRecordset( "Select * from t1 WHERE t1.fio="  "Иванов"  ";" , , dbRunAsync)
  tt = Timer
  Debug.Print mSec(tt, tt1) &  " мс. Rs: "  & rs.RecordCount &  " rs1 "  & rs1.RecordCount
  For t =  1  To  100000000 
    t = t
  Next
  tt1 = tt: tt = Timer
  Debug.Print mSec(tt, tt1) &  " мс. Rs: "  & rs.RecordCount &  " rs1 "  & rs1.RecordCount
  rs.MoveLast
  tt1 = tt: tt = Timer
  Debug.Print mSec(tt, tt1) &  " мс. Rs: "  & rs.RecordCount &  " rs1 "  & rs1.RecordCount
  rs1.MoveLast
  tt1 = tt: tt = Timer
  Debug.Print mSec(tt, tt1) &  " мс. Rs: "  & rs.RecordCount &  " rs1 "  & rs1.RecordCount
  Debug.Print  "---------------------------" 

Private Function mSec(a As Double, b As Double)
  mSec = CLng((a - b) *  1000 )
End Function

 1 -Async						
Время     N1      N2      N3      N4      N5      Среднее
 1           10        0         0         0         0         2 
 2           2574      2273      2314      2304      1872      2267 
 3           1872      1883      1882      1883      1873      1879 
Итого      4456      4156      4196      4187      3745      4148 

 1 -w/o arg3						
Время     N1      N2      N3      N4      N5      Среднее
 1           0         10        10        10        0         6 
 2           2254      1872      1873      2814      1873      2137 
 3           1825      1853      1853      1853      1853      1847 
Итого      4079      3735      3736      4677      3726      3991 

 2 -Async						
Время     N1      N2      N3      N4      N5      Среднее
 1           10        0         10        10        10        8 
 2           5728      5728      5728      5719      5728      5726 
 3           1862      1862      1853      1862      1853      1858 
 4           1833      1843      1852      1843      1852      1845 
Итого      9433      9433      9443      9434      9443      9437 
без цикла  3705      3705      3715      3715      3715      3711 

 2 -w/o arg3						
Время     N1      N2      N3      N4      N5      Среднее
 1           0         0         0         0         10        2 
 2           5588      5658      5588      5598      5588      5604 
 3           1863      1863      1843      1832      1843      1849 
 4           1842      1842      1813      1823      1872      1838 
Итого      9293      9363      9244      9253      9313      9293 
без цикла  3705      3705      3656      3655      3725      3689