MariaDB 10.2

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CREATE TABLE t
( 
    A varchar(2), 
    B varchar(2), 
    C varchar(2), 
    D timestamp, 
    E varchar(2)
) ;
INSERT INTO t
    (`A`, `B`, `C`, `D`, `E`)
VALUES
    ('a1', 'b1', 'c1', '2017-05-16 11:46:36', 'PA'),
    ('a1', 'b1', 'c1', '2017-05-16 11:46:37', 'PR'),
    ('a2', 'b2', 'c2', '2017-05-17 01:34:28', 'PA'),
    ('a3', NULL, 'c3', '2017-05-12 19:14:15', 'PA'),
    ('a3', 'b3', 'c3', '2017-05-12 19:14:15', 'PR'),
    ('a4', 'b4', 'c4', '2017-05-12 19:16:15', 'PA'),
    ('a4', 'b4', 'c4', '2017-05-12 23:16:15', 'PR')
;
SELECT
    A, B, C, D, E
FROM
    t AS t0
WHERE
    NOT EXISTS 
    (SELECT 
         *
    FROM
        t AS t1
    WHERE
             (t1.A = t0.A or t1.A is NULL or t0.A is NULL)
         AND (t1.B = t0.B or t1.B is NULL or t0.B is NULL)
         AND (t1.C = t0.C or t1.C is NULL or t0.C is NULL)
         AND (abs( unix_timestamp(t1.D) - unix_timestamp(t0.D) ) < 120)
         AND NOT (t1.E <=> t0.E)
    ) 
    AND t0.E <> 'PR' ;


A
B
C
D
E


a2
b2
c2
2017-05-17 01:34:28
PA

a4
b4
c4
2017-05-12 19:16:15
PA