SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3947254512ba21637d039efb8a48457f8770eb535fbdda10825a0f37f9e5a2da' 
  AND token = 'IWFzKOIDLJRMO4YmokBjDZMcr8Jybr1a76f0XbPBoCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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