SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1435307a85adb048160f75784c10004748ac4e85d1fa2a80f774fdd40c2b465' 
  AND token = '5oSweeIbFf4ozSFxgg1Su1eEAJjZtOzl98NgrKTHZv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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