SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1f0a375a4a6b2dc3702622e30d4bae6495a3a8b42e35f7092d37247ee7fb7389' 
  AND token = 'EXaGuiR0AIfGihUF3FvP6ybL/rVfTl+jESJKVCjzCLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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