SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b8a7ce61f8785bbd21399cc27bf134f3d4e9884a03a7e071a6c51f6cdb16989' 
  AND token = 'VNznsqEv9cC7Zk0bVxJkGkX/GQ7/AjQJB03QMsVdj5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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