SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4490b4aa89303668d99ef1dd9478abb4fe7c59d022767f960dc592fcab43bb6' 
  AND token = 'ohPFVq7WQsrH1kUiOCL7RDv9GcxJ2MtZ7iiMl1VPr+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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