SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03ab1e45a172717bd1210d710ce568b92053540c188078544f0969d469e116e1' 
  AND token = 'WilMO7CJ4GOisIIZ0kBDA+yS1lJYBe1WhNBrurfhyHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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