Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9a0e4682b53f7cac2fe5a5101e440730250a77bec9a08b464e0ea4dcbeb93b5' 
  AND token = 'BQrx/Pak+YjmufvUldpqEVTxeF/8rNlK8Hl8jKF5aw0=' 
  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"
    }
  }
}