SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ecee0130184a47e89cae2fb3dbb1bb45329f6786686b4a481ef47afd6f1ae83' 
  AND token = 'JBHInJ9WsyyI0WAYsZw11H+Qr+UsXqNS8+Cudd8EmUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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