SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '521794be85e54715efe1e3489c2e2126b7f0739ae1cbf977fe15fbcffc58f78a' 
  AND token = 'x+bjXMs4+hGqij7N91k0FTTHX5rAVpdqxR3PIR98IhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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