SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e1c2e9dd4b53e72b689c7647b7e846e489ae716c490392dee47b367856cf22f' 
  AND token = 'YpZujBK5XDizkruDYRKHRh3n7LK3WzH42/CzBNw23fE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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