SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3915384a7a26e8d90e092334281cbfbbdc1fdca7c732366b5ad68b83cd3e7ffa' 
  AND token = 'UZ7fnvTORJqLVKaIpCWGCqa8yO74yz4W/AMWabKXlUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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