SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '200fe46a1fe6044c25a87ce8505079b7cecf4c7f18738a38b1441c23766eb1ad' 
  AND token = '1VgXSye/uUCGSt+OJx94gyildjUF1FlDjRDbGtTzawo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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