SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c93b989ea9a667227b07304f8efe21605c176238a9105d1ec34332b677055aa5' 
  AND token = 'kWkDqYsWOxyzDTc5ICicClgKd2ATrfiSvUTI9/I66RU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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