SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b7be49fbefa905938f442a871b53c46dd27e425201c5f21b083db8ada0c81ac' 
  AND token = '1AvJXyHViWmxw52BC9X4OLuD89QAPITKQ3HO7cnQNgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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