SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae4b1b11d9add552ff9b461224334dc03273b81c7518d6dfc25cf1c2396976e7' 
  AND token = '/XmXNwZbS1fh/BoUF+KVuoJ/0iSvkpMsIMCu5U88q3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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