SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5d7b5cd723cf463e70fde8a100cd05fdb6a98ff7fec15991c338dd414246eda' 
  AND token = 'Zswz37sOWRd+91P9VjtucTCs+Lvsze5m1yk8O2HoTpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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