How to query one DataFrame with values of multiple column of another Dataframe?

Question

I have 2 Dataframes:

df_1                                   
     A1     B1   C1    D1
0    4     64    57    51
1    7     1     14    69
2    47    21    56    47
3    49    52    36    87
4    74    39    7     54 
5    96    16    32    44 


df_2
     A2   B2     C2    D2    E2
0    5    64     87    5     14
1    56   47     68    67    16
2    7     1     14    21    98
3    47   21     56    23    45

I want to check all values of columns A2 and B2, if they correspond to columns A1 et B1, then I create a new column D1 in dataFrame df_2 that correspond to the value of D1. If the values does not correspond to any rows in df_1 then I store Nan.

Here, values of A2 and B2 in rows 2 and 3 of df_2correspond to values of A1 and B1 in rows 1 and 2 of df_1.

Expected Output:

df_2
     A2   B2     C2     D2     E2      D1
0    5    64     87     5      14      NaN
1    56   47     68     67     16      NaN
2    7     1     14     21     98      69 
3    47   21     56     23     45      47

I'm working with 600 000 rows dataset, and I wonder if there is another way than using loop in df_2 to query df_1 to do this task?