SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '701bee72316264509873fc4ec3431d8a9dc6047975c0da163877ab65da7134c1' 
  AND token = 'hy0kxM7pdtWLhzlfNgr0wuh65y39ZYH5d2SxljL1qWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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