SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0c9a748b0883e6a5fa95b1e98d60b6be3e48d81198541a43d5a9bd26b42d521' 
  AND token = 'PkTIID2RGAYJv5hzCXYwH9EI4UUoUimoz/QjxEKt3lY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00071

JSON explain

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