SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '56d63429a9ede091d1172da2987f1b4fc603891f22a5738bf280deea33119505' 
  AND token = 'JWVbGysD3selhW6z02o2PYdwyyK9IVZliu3EYlntZ8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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