SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fe9d1075d0935a4b9608bb29168224b2b9339eafed3a607d574e2ab0788ef46' 
  AND token = 'mDNK7AGH27l+E4E4usyhVeUIVw9zNKR+VvBUDs5GMXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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