SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7cbe7053e493a7d5802e6b6c13ded48f109f50997b476f7eac3af52ab169e14' 
  AND token = 'nhvQ4ZJvIsflbVDH/mqtqJlWnq6WvrBY/iDkaxFhrpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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