SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d51aaeeb18f2adfa6bdfbae87cbf0a7a651695630ec3fe0eddb328ab50c3eb6' 
  AND token = 'WdDlRRGmRN3m1UCFCg40Qq2IRGSSsenmQ7zuB/WfXeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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