SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af148bd8555ec71eef2b06598e60229f3d9209680da024ca74ffcbd43ea6cc4a' 
  AND token = 'YnbmpzlNteIf9xjOxosrR4HFoFXdGc4lRJtjgN9l5cg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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