Solution:
I had this same issue as well.
According to the MemSQL documentation, you need to configure the client driver: https://docs.memsql.com/concepts/v6.0/prepared-statements/
In database.php, add in a new options key.
Here’s my configuration, it’s pretty much the same as the default, notice the options key.
'mysql' => [
'driver' => 'mysql',
'host' => env('DB_HOST', '127.0.0.1'),
'port' => env('DB_PORT', '3306'),
'database' => env('DB_DATABASE', 'forge'),
'username' => env('DB_USERNAME', 'forge'),
'password' => env('DB_PASSWORD', ''),
'unix_socket' => env('DB_SOCKET', ''),
'charset' => 'utf8mb4',
'collation' => 'utf8mb4_unicode_ci',
'prefix' => '',
'strict' => true,
'engine' => null,
'options' => array(
PDO::ATTR_EMULATE_PREPARES => TRUE
),
],