SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '873093d26292c236122dc9f26467df72fa123967aa8dfe5ffe50d20773c5e813' 
  AND token = 'pJ7E240NexTfebglGsZyZDxgim09mUJByurY7L0MOHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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