SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b759f48166f57702373ffe9aa82dfe231d1cce6845c426f013fadabf6b13730' 
  AND token = 'vsNOef51vayAOLupYTReH2ZAeBez0XQfmoZRZnLOHAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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