SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bd21e92c46d7d03ebc133faa0de0c95f52b1e661d439ecf262b2624731b4e800' 
  AND token = 'utA4BUYWRjwLFNgucyAO1uGDxHvnAHDTRDq+sLbMZro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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