SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '315f60bfdbbffed9fcec2af3c1750edd290c4120cb4b3e8a9dd65e8bcfc953d5' 
  AND token = 'aeMC6S0KfWtfcDa4AF/XjVIhFLpjERbTjMMHt8N0njM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}