SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff30cc3409d59e35a16658c228a3e35fd65eb05e2e4061611714eb12a1ded709' 
  AND token = 'KZQPyWbLB0ytk5xnVl29xogc4LqMWLnHfOkWnMeVJ7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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