SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cb9ef67053f29cf3f5f99c3971425e3271059ac424f89dc143fe523f21483e9' 
  AND token = 'JxZjXt9oYqOUaj1qa4RKZdZKqWZ/Czsv2FyEVzu9oVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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