SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd4092889ea3a47a7c4b39fd9c6a225b751f042f63dfac0cc069f5641e41ea4' 
  AND token = 'UW6qwuL9YbAWQkUMHNCsbPDw6VgGIVh5bzgWo6sSNBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}