SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0311ae1b019b449dc48effc97956d22bbaa99868fb1ed0b353c21204d4b322a9' 
  AND token = 'ueqZ9YuOpFAFInnu37oGFy1gEbmOCDfgKCLfatq+hxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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