SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ff61f77a013d264bf734564b59fd49ce4cd2b11032eecb72265c00a5087896f' 
  AND token = '8vWK+HJNGQqpmEeiKNXl5o9kWBDzCro9VRxEIXKuw/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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