SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9915c4cad94dc56be505fe87e4c93f2b8b98ebefef51a248dac8a583b4fe7a75' 
  AND token = '2tAEXzybh6M3EaqfhgWCw8ywMopXwoMdVpC3ulVHjbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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