SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '16d42e6b286bdb10b237a2bb31786d742b71cb8806721533f75894cc2cc300ab' 
  AND token = 'SIfUxgxGzMfrJ+brXgzFNPzHlYzCXE+MydMkHfHDBMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}