SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd460b56bfd7e04c4cf3debf558d3b305f363f8055c111234447730affd1957b0' 
  AND token = 'awDRUT9MvafHvsoLmRW/DIAtsS/GCpPHlcxQPQkk0zU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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