SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a9583a0cd6db0521ce0319ddfe06ea0d28dc8dcd2a02fb7ca26aef3b685d3d9' 
  AND token = '03m1uD7gmyb6XXpi8FXZiIBYWNxdWsTdZS4gYaJ34VM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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