SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b5f1637609e9e81bc00eadbbf8fa13f221afc4501529c1ae74288b336e81b60' 
  AND token = '+qKFTNUAqnTXM+GYmMIptJFANhffZKqs0kVIfcVU3Sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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