SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '945796c4e86ddf379396ab82109735dc91d4b1df6860a2778ffc716e5a24dfac' 
  AND token = 'Hmvb93yg+CFOYKUFKl198QyeETvE/wbCvLtOABMXOls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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