Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '839cf99639559f980b95184a9640cb5c1ac31b84b5c56f23e2beef8fbeff1447' 
  AND token = 'Ln5c4IZsrDlnKovWqvLwhpKLGTgzexjMreg2DPgiWMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}