SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9db6c2724b9428fe7ffb17267007aae409de644bb8cd80c9fc15b649c230dbf8' 
  AND token = 'KXtH063N6/7zD4pRhSgcPBYjPNh6fZYFy2k8CfqYzqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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