SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af609732196f1dc466d66b7a02ca99874d1e2ae1eb4ae2fa9a03f8444a18ad8a' 
  AND token = 'opCW1MtQvknfWIjcObno2qai5BaLBRzlCoTwAOWdFZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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