SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ace9c9013bb3171f9ba93af2532823863f2b7afd9d9071242e441412441bb6a8' 
  AND token = 'vLAhiohdFQKfkOWUoZT7mtil5ehEo9PX+2PR8PdrrEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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