SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf2eb3bfe6b048914423dbe3d2c325f1a82212258ea21e429a773e72fc65586b' 
  AND token = 'KDarygAeQWmxOJ9ugQEZzuaCj9dng9JklS42w8Lwmb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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