SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ebc738d12716817bafd27efbc86cb5ec1dd13307eaa5325f699c03132a3104b' 
  AND token = 'UDuPnzYYhMi04oeCxfySY/G8lemVNOkFgdtXPXFx6ig=' 
  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"
    }
  }
}