SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8b048fe18cb1ab7818fb833f590d5cd53462f82bdeef3432ddaa42169a9f92c' 
  AND token = 'yUhARiMhDlTBy1+sGL79C1u5zsMZiZKzFAu/HOGedi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00260

JSON explain

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