SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc21f044e0ba4f43a3efb6ab2ffeae59c5c9153626ae25a2cea0804c5b93773e' 
  AND token = 'lwavN2URtxaU7ytFwSDc8d+DZMPUhBTZTzFy/FTVFjA=' 
  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"
    }
  }
}