SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '36f1727518cddd4668b9f7f500591b1a45af6957020623b7b9d735e817044abf' 
  AND token = '3QtZy/d/vIlwuoiXWz8ZRxfpiyyMO1v0kxb98lAPKqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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