SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bdb4f86ecc5cfad9d41d857f5ace76ca2611184e842dbc7fe61f1e32daa81c7' 
  AND token = 'osEgR+Uq4l+2JsWVIrCxJ6bqtn9ieMLG9ZuFxP/DzvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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