SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64c9c2d99cbce0a4d68d8c39a5547544245a50e766548972b6bce3ca329fb43e' 
  AND token = 'Tr30znPh+e0atY4fReRPJ/y7hUija7SXRnxvSlWgb7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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