SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fa862a55962ef572b45bc74d12a612880a28622dadaa8c0f2aeb3fe112d3299' 
  AND token = 'pRwcrWi5HmoAYcpDfkzwD4pEei/VFP4aAWMMiavuhe4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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