SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1410a8ffc70b93105c3455c2ec86a9c88e0597a26bebc3cf5b8334615fd06244' 
  AND token = 'wMQ4qNZP2tDLqTRPwT2tn8sVPRdGAhrvVogHBfwdLJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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