SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68c012db3987edf7229365ffecf88d00ecce2b0ddea1ebaa24d04ea5ca54f17b' 
  AND token = 'vkipFuRHJOw7q9r8gPySOReuosMYWoR/WeNRTLMGDxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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