SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8044b5aecf119765ae1510648a8a4ad9612f60844aef8e605fff33e5333f87c' 
  AND token = 'kN21PA7I07TC2BXl8V/n4Ud/zLI7XtPgZ19jjbYWya4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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