SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73aa224572d14ab61c972ca3b02eaf388c1e8e98f20d35c05ec5dadf9291308f' 
  AND token = '3rwth8SpuGg4oKihmHvMnJwX6oe7h9my/gPnneHZEBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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