SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d83e1fe4a5f20cbed0b64b7724c1f715f08e70115d1cc2ab6392a4b5daa0176' 
  AND token = '8TQpzR4jGoxRq/h45VJpI5GQpwLHnF/tPQTZMlL+jXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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