SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '269481c67e575df5ed758ed79bfbbc76d8e570307c63ed1afc02965d96b1e711' 
  AND token = 'AClznHOJogKzsj6c/B46wocblwxhrFLqp//1RcHM5IE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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