SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48bc3c8e6f7a9417c77c2962230d4652a4140dda3e0f82427ec148ec88aef21f' 
  AND token = 'IWdfd12GAHMKNdj4EvsCIYLLtdZT7WARrESb53ZkG+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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