SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60ca137db801251eafc1a9a4cf3a101112985a11417cdaf85043cba297c27762' 
  AND token = 'ewehtDuGK2R2ylZzleudYdqKVlLMj6lkveEHVw6l8nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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