SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59505d3c9c92394663eda191edd8425c0a433e73d36cd4088ef8887b79d24980' 
  AND token = 'emvbNPMQmlUyljjthhvFgY2h/SKVXX+pYZady5hqDA4=' 
  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"
    }
  }
}