SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '920c1b177ed3f322810ae0b414cf2d8db27e58971e2ff5604cbb303926df63ec' 
  AND token = '2EJdxuznIiJ1+2dO1/ulC1EdOzA3WXrDbFUK708GaaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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