SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5254efe03dce6eacfd0e00542ca6a59dcca6d710170efdc8cd76650de295d341' 
  AND token = 'YHUKnDf+hNY9lfgFfg5xuQHNrt62YCMWxm58Eh+/glM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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