SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6176345f493b466cc1ebe2f8d86b5867d0f325f74e7b93d60e0ee45934885c32' 
  AND token = 'tWV3rdv9pFyEzKlFKtMHL3pdhUZSlqQjZ8IfJLVEInA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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