SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da92938ebc93ff019bca67b1d3026e9412d119a25a543c0b95f96aeb06c057ce' 
  AND token = 'vJNzhXCqszw0Z4HRSjAvLG3aVvRKDCVKcm6B4kDrXxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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