SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '712d983f885635475c8c4495a4de9f6fd14914cb4458e6e2123ef716363fe93c' 
  AND token = 'TKZvwY1rQjw1Weyz/srEbYCWoAzP4jUt88db6GPt5iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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