SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d6fa565ca0bafa5803de51182f86e2eb478b14d0d75e5a553b81e3d386eb1a5' 
  AND token = '2/nyXF3Z5T2dZViqVRmYOHc7CidnhELJQ4HbLzWgjag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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