SELECT 
  CONCAT(u.firstname, ' ', u.lastname) as author, 
  b.page_id 
FROM 
  cscart_blog_authors as b 
  LEFT JOIN cscart_users as u ON b.user_id = u.user_id 
WHERE 
  b.page_id IN (
    145, 137, 138, 139, 136, 134, 133, 132, 
    130, 129, 127, 126, 125, 124, 122, 120, 
    119, 118, 116, 104, 103, 102, 80, 79, 
    78, 76, 60, 58
  )

Query time 0.00104

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE b range PRIMARY PRIMARY 3 66 Using where; Using index
1 SIMPLE u eq_ref PRIMARY PRIMARY 3 mahm3t_cs443.b.user_id 1

Result

author page_id
Krzysztof Ksepko 58
Marc Böheim 58
Adrian Daniluk 58
Krzysztof Ksepko 60
Marc Böheim 60
Dariusz Żukowski 60
Adrian Daniluk 60
Krzysztof Ksepko 76
Marc Böheim 76
Dariusz Żukowski 76
Adrian Daniluk 76
Krzysztof Ksepko 78
Marc Böheim 78
Krzysztof Ksepko 79
Marc Böheim 79
Krzysztof Ksepko 80
Marc Böheim 80
Krzysztof Ksepko 102
Marc Böheim 102
Adrian Daniluk 102
Anna Pawlak 102
Krzysztof Ksepko 103
Marc Böheim 103
Adrian Daniluk 103
Krzysztof Ksepko 104
Marc Böheim 104
Adrian Daniluk 104
Krzysztof Ksepko 116
Marc Böheim 116
Krzysztof Ksepko 118
Marc Böheim 118
Adrian Daniluk 118
Anna Pawlak 118
Krzysztof Ksepko 119
Marc Böheim 119
Anna Pawlak 119
Krzysztof Ksepko 120
Marc Böheim 120
Anna Pawlak 120
Krzysztof Ksepko 122
Marc Böheim 122
Krzysztof Ksepko 124
Marc Böheim 124
Krzysztof Ksepko 125
Marc Böheim 125
Anna Pawlak 125
Krzysztof Ksepko 126
Krzysztof Ksepko 127
Marc Böheim 127
Anna Pawlak 127
Anna Pawlak 129
Krzysztof Ksepko 130
Marc Böheim 130
Anna Pawlak 130
Krzysztof Ksepko 132
Marc Böheim 132
Anna Pawlak 132
Krzysztof Ksepko 133
Marc Böheim 133
Krzysztof Ksepko 134
Marc Böheim 134
Krzysztof Ksepko 136
Marc Böheim 136
Krzysztof Ksepko 137
Marc Böheim 137
Krzysztof Ksepko 138
Marc Böheim 138
Krzysztof Ksepko 139
Marc Böheim 139
Krzysztof Ksepko 145
Marc Böheim 145