SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3c949c73b7d17f44e77169955942a85f0e8db5f130089440fba92edcde044da' 
  AND token = 'bmNwoMhDlSyxT3wKbEBXCRb002rLaajcIRTrf5zLBlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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