SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf394cbd9ef41fa001f89d8e85306eaf8e3b97783f7be616e08466afc109a500' 
  AND token = 'CWfpXKSJQ2v0iwtL5e8kyB0jd321tteCjFUh3rjlSco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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