SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '656ba2a525c3e8da7b417b65286fdb817b4fa9466251a3b57b6c7612a6a39a20' 
  AND token = 'u210KY8yjAzlmIVXVXO8MsQPMLhdYGjJXVn+CPmh1Tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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