SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69768932548c872f5e16de933c10add45a2755ec89916517605e3707ba254e15' 
  AND token = 'jMg9FfKYh4L7au+wSdLGFUcsqeqZASawIzK6ndJWfIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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