SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f152ca25cf30978a8e2b93acad6980126dd7d583dc29fa42c97d1282a2ca404' 
  AND token = 'LR/HoSkaV8oJknjsMgfnT6qbPQgbY6UVziENN4deAIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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