SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '131a931326229fd40d8b860a9d566bf0d9aa30e68b9fdf04342cb66aab653f1b' 
  AND token = 'AHHwLZet8vOfzFGF8IRsThbAPzEaUFVWYV8zZCt+zCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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