SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad4830a98fe10aa7d3e64a964da2b8832c05f0463673ca703b1c4c74ea575622' 
  AND token = 'jS/zuE5qha43wglGeylNlZk0c7scKBV1g9Jox+ZlUJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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