SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f0611744ef9348319bbeacc52f30a9933fd45731582460c6f3b62c22b0ce354' 
  AND token = 'WTbZj16phZo0ts19A2m98ogFXlSvpxigU5P3sT5lujE=' 
  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"
    }
  }
}