SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03d8542e971dd30b320effe96eb43a72ca998e005e7c608424dd3acb70ffb189' 
  AND token = 'flKSwa+qfbRDx67GBeQIn8wsxasDXlYEfH8N9pROD/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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