SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57f95645d5cfc299f1990b3882bc53727e2a3c020052968c5a31e8580c29523f' 
  AND token = '3sJJVYD/+5YVdIeh2+hWSXsxilOx7hsogRPV1P7mAoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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