SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '653752f6ac81b06cce40b60a401fd9b9a5506f6d33f1be186ff71acb7ad34329' 
  AND token = 'xu6Vgr/3yLUvRfin4GrPssT5suOkzMJ9jvuZKjvWrrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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