SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f2fbabb8a56c6b89967ac80a5bbf902af75d768eaae7a7bc7ff95d41ea8b1ee' 
  AND token = 'wHArUiDEDysL8IXwEkuqvP43zIvL/zoG3KeclOrBzPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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