SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa79c3744d67254796832e3a7656f774f80c6d2d898ba9fd7ad949ccdf10e340' 
  AND token = 'd2xApSivuNZcRyX0WHtnnF+Be0iwaI/5SDUkJJY6otU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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