SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d9223145626eac85cd673186f48b162912cf2d331495594eabee351f234ad43' 
  AND token = 'w6owyiWL61ftlZzRKraYWyYGUydrmvVuzrNHZwR4Ois=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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