SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63133637f0b46547b9a27828f6a529e053567791dd244ab478309823c759cf5c' 
  AND token = 'sQyZPNpn97c+ye2vtOyh3EoxtgQoRnUSpOiOMcc1Qzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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