SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f7e8d88d453f68298646af11043747b175601dadfc2639235ac2d0f6e6ac8a4' 
  AND token = 'HU3hqtTiUR7qTKg968A9xjGhMBQdBXuTASn8sUjXwvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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