SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dc8fc21b8359ad4204053b9aff1eb6fdbd596716c62805b5608f10ebbc40afa' 
  AND token = 'vGgj8OL8bgn5QeoejVgQbKixO4qIiM9cZXOTZuKSGDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}