SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7b40e45abfbe145ef1358c7040d283b87caba610a5885c1829e7cd20d18fa882' 
  AND token = 'AYGWPKfWd17bjI/07ISB6hjC+q2mefRNUiQ1y9OLtvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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