SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '828b40a70a1f8bd99785853560cd6785af9f6645657df1f5a281bd46bb7f24a2' 
  AND token = 'QjIEOSRyFxneK+9Owu0L06AJlNgGS1YPAjlI69Jdeic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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