SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '782392826eda86d698537c95a76a2624960e541cac1781d9936286a15e8fe98d' 
  AND token = '41P9qezho38bL9BnkJxEkLg0JAmcBPWVpNJSQcjWTeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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