SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70f6f75458694f41d538c5c206d3cd9130e94562140b7198a383ce398bc07937' 
  AND token = 'xfoGI6XSdImmP9FehqKsqPjwPNvzNq6QC8sCZJX7kIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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