SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20217e690bab3e6728b93a59e76244156438d56140854a543f73dfd46ba4294d' 
  AND token = 'rUswiiZNRdbWp8fpyWGKvklyK5GZJYlaXl2qqEuBu+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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