SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59360a1a15b133e0693f399fe1312c074055c847e2d384b532eaded6c21919a3' 
  AND token = 'HBWOlf6TVgF33ErwcfK0D+YQpB/aB9ji9Iygf1CsDcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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