Almost identical MySQL server totally different performance

I have two servers which differ in mysql version - Server 1 runs with mysql 5.7 2 cores Intel(R) Xeon(R) Gold 6248R CPU @ 3.00GHz and 6GB RAM - Server 2 runs with mysql 8.0 4cores CPU Intel(R) Xeon(R) Gold 6128 CPU @ 3.40GHz and 24GB RAM, since this is an **mysql only** server. Server 1 runs in production, while server 2 is currently my development server. I use a software, which sends e.g ~11k selects on my products table, which currently holds round about 150k products (so its not that huge). My problem now is that **server 1** is done with the same task (same data) after 2mins, while **server 2** needs 18mins. When I execute a single example select SELECT link FROM products WHERE concat(sku, lieferanten_id) = '130928OR1'; MySQL on **server 1** retuns an answer in 0.05 s, **server 2** in 0.06s If I repeat the same select **server 1** is done after 0.00s, while **server 2** still needs the exact same amount of 0.06s. Below is my /etc/mysql/my.cnf

#Max MysQL memory: 662.8M

[mysqld]
user                           = mysql
pid-file                       = /var/run/mysqld/mysqld.pid
socket                         = /var/run/mysqld/mysqld.sock
port                           = 3306
basedir                        = /usr
#datadir                        = /var/lib/mysql
tmpdir                         = /tmp
lc-messages-dir                = /usr/share/mysql
skip-external-locking

# GENERAL #
default-storage-engine         = InnoDB

# NETWORK #
max_allowed_packet             = 999M
max_connect_errors             = 100000
bind-address                   = 0.0.0.0
skip-name-resolve
skip-external-locking

# DATA STORAGE #
datadir                        = /var/lib/mysql

# CACHES AND LIMITS #
tmp-table-size                 = 1024M
max-heap-table-size            = 1024M
max_connections                = 100
thread-cache-size              = 64
open-files-limit               = 65535
table-definition-cache         = 4096
table-open-cache               = 4000
group_concat_max_len           = 320000
thread_stack                   = 1M

# TIMEOUTS #
interactive_timeout            = 300
wait_timeout                   = 360

# INNODB #
innodb-flush-method            = fsync
innodb-flush-neighbors         = 1
# innodb-log-files-in-group      = 2
innodb_redo_log_capacity       = 67108864
innodb-log-file-size           = 32M
innodb-flush-log-at-trx-commit = 1
innodb-file-per-table          = 1
innodb-undo-log-truncate       = ON
innodb-rollback-segments       = 128
innodb_buffer_pool_size        = 18432M
innodb_thread_concurrency      = 4

# LOGGING #
log-error                      = /var/log/mysql/error.log
log-queries-not-using-indexes  = 1
slow-query-log                 = 0
slow-query-log-file            = /var/lib/mysql/mysql-slow.log

# CHARACTER AND COLLATION #
character-set-server           = utf8mb4
collation-server               = utf8mb4_unicode_ci
explicit_defaults_for_timestamp = 1

Are there any values I totally tuned in the wrong way? Or is my **server 1** just "faster" because of MySQL 5.7, which uses query-caching? If there is something I should also provide, please let me know thanks in advance! Edit: my pastebin link contains output of **mysql-tuner** and SELECT name, count FROM information_schema.innodb_metrics ORDER BY name; from my **server 2** https://pastebin.com/yBScuLLZ