SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '045e5a33f49c429d2ba51e59dbc4b2881795790d8b727619daa14fadb5abd65f' 
  AND token = 'HubgPutvuGVmQO5rCBiuA9edNPqMZMNO2XtOO6Fj2q4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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