ActiveSheet.Range("$A:$A").AutoFilter Field:=1, Criteria1:="*" + SearchTb.Text + "*"

Private Sub BlockBtn_Click()
    On Error GoTo ThereWasBadCalculation
    If Sheets(1).ProtectContents Then
        Sheets(1).Unprotect
        Exit Sub
    Else
        passwd = InputBox("Please, enter password: ", "Setup passwd", "")
        Sheets(1).Protect Password:=passwd, AllowFiltering:=True, UserInterfaceOnly:=True
        Exit Sub
    End If
ThereWasBadCalculation:
        MsgBox "There was a problem when performing the calculation"
End Sub

Private Sub SearchTb_KeyUp(ByVal KeyCode As MSForms.ReturnInteger, ByVal Shift As Integer)
    On Error GoTo ThereWasBadCalculation
    Sheets(1).Unprotect
    ActiveSheet.Range("$A:$A").AutoFilter Field:=1, Criteria1:="*" + SearchTb.Text + "*" ', Criteria2:=TextBox1.Text, Operator:=xlOr
    If SearchTb.TextLength = 0 Then ActiveSheet.ShowAllData
    Sheets(1).Protect
    Exit Sub
ThereWasBadCalculation:
        MsgBox "There was a problem when performing the calculation"
End Sub

Private Sub Workbook_Open()
...
If Not (Sheets(1).ProtectContents) Then
    passwd = InputBox("Please, enter password: ", "Setup passwd", "")
    Sheets(1).Protect Password:=passwd, AllowFiltering:=True, UserInterfaceOnly:=True
End If
End Sub