SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed5a8f086671d2e86baf9799248cc97e561324724f7c64a01e2e322bb69eee67' 
  AND token = 'KAcRl7gjtihpJWZCv2vU5xm3DmKRMkdM4V2HgNi5S54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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