SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c668f5a4fbaf7916637185e35b2ce96e80091ab5da734519e0e56b40416823b6' 
  AND token = 'ztXv7OLDznmenQ2jfVU5FRNOe+xfLIXkh9NGvMnTNyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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