SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5664ad8a8b0d0ee50db32fab57f6b298f9353b06985db723bd83b1f26fa2b144' 
  AND token = '9FTUyhm228stFTk5fGa5LgjSL/XwmxnEPq8SucAc3gE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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