SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cde90e77c299a292035153b2ecaa589e8d95b834c520702d15b77186518b69f' 
  AND token = 'GFQtqveFMxUYA/c4O8FiBmXxN2IM5Ks36hjr39DViYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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