SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4f1a522f82f80c9ef7be69f806dad5330278f00e7146f59a59fde12db2810fe' 
  AND token = 'LkUY0+zQ9yds6VPucxbFE8ePs5w2I9mgYI9hVGEKYMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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