SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '44eb8b88bdc142621d7a86c8cd5fe35cfafe81db4f282fca5cb2b673cce7e035' 
  AND token = 'fvc7clSJw30pYzR8qn08fzuDDVzjU36tqVVB2WCggWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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