SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a70501534933badbfa680834229457d388d6b37fe3b5366e8477df72c9316333' 
  AND token = '8mDJ8sguuzZnqseeSmvwhymAu+Dqn3+woWYcg91R9o0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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