SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0da064ee23211543c692605a9a43d1fae4f6b177f971d7f5ac9a60be6396575b' 
  AND token = 'RMhJBccZgwK0WH7DlDEqDgqX8isShX9R66kKRxHV20E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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