SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d71482ca8cb8db4e52d850f5c90552f455606915cb3548998c30a157ff844e3' 
  AND token = 'D0l3ZS1bkUu8bhf+sba0k2QNHV5ppgOjWWKKCvdZ5sM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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