SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4e9845e6676f39ea59ae50a5444933d0201b07172b54f7fdd352ffc9ba869074' 
  AND token = '8mQ+j7bui3me7olNXbp2wF4P7Er2IXfCwiB97/QGZy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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