SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d628343d847977fb3cc0ac5fec858a23044aa8d2775f958119fea31862fd73b' 
  AND token = 'cHJMMxpOG1KCGRMKdJq01KdzQ6q51aDM9zmYzdGwjXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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