SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '696b4ecf13447054248112042e0bd4ddbe6c1f19b1e6860c317d827a8911ff9d' 
  AND token = 'mAoQZd59XgrvkxJBG1QUzM3t5tfLYYjqHDsXBXQuB70=' 
  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"
    }
  }
}