SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd730d547260dabc5936cad4226864592f6475698c1586297302075f94fd25f4' 
  AND token = 'rKMgqIR7C9bbMI+uiepcSbe6D83KvGNhS9dXfLWr8aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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