SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24fa86da85a2e52283e1bc2924ccc16a8d7477e1f54b43830e7c3776701482e6' 
  AND token = 'zh8G/b0egdiAtq72xyIFQ/ybcm2xORBKkMEPcNeMua0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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