SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c269a362048c2fbad38ea45d7ffd24fabb69ca104bed40c896292f0483ca3c5a' 
  AND token = 'fhyva67dio25JZq7WTM6IMXBWs7K/IyyScrIJSngxZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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