SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d1f5d53b8c82814a06994f2a0d7288bda61535e94f4b5846fd160e528af3339' 
  AND token = 'VZVvUshp5iQHD5J22BUh7bD3PtA/Z7Oz1THOqP6DrMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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