SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3092b141f938518191ea2ab27392b0fa4a30d8ca9ed8fb32024e5f22992f7c47' 
  AND token = 'rH94yrlhKD7WDc3PR6qIZ0ACVxf0W+5V2CHaV00QCHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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