SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdab8a2152453cd346ddced768270a150d6327d3ba8334429c7c4f0fbcbdc997' 
  AND token = 'TKKvd0pDK8J1g2KvHZ0WUbWMQin/oQOWJbUWGZtlR9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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