SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ef8960826e46ae2a591d5fb3adb5443a556baf2b6367b756a76c853b45c7c24' 
  AND token = 'PCOiAujf1dM33DqorMnjeYuaevm9grE8nkfImLqiO6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}