SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4dd491aa312cd67aa5cd2ff552f92c301c1393e8d165b0ad5a8e976fe31b9632' 
  AND token = 'Z/OIfxn1YyVLHdn4XoDKH6Naqgo4KVEC33JcUNnODJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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