SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b67532c4021f4b94dc53bb872b932c100b0d4ea6cc29645db847b431d19e937' 
  AND token = 'KixTfdn5trWesqurEG16zS1muKzehxOEu3mvKlHhAl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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