SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94831cf344b8eafc4fcec48910702d48db1797d97920b26f370542e9fd8b857b' 
  AND token = 'Mq8ax2bfW3Vc/hwosadYYk36k/WJXUEhbJg+tq0usDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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