SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97831fccae1ce3732e1a247c48819f30bc96f6ec91baa9badc5dad4cf9142ae1' 
  AND token = 'l38OkSrpIp0VxXJkc/Ag4L1WX8IT03YlIFlkux+EGD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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