SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dbc9689300d780ca56dde30565623b8962651d604310446bca3aa8a365323333' 
  AND token = 'gLS1qbN5uOgfYJ/A6qhCGpTSKLAmT8aaPl6X3megwS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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