SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '85f5336e20f6366aa356eb342188e207e8c01daeb7d443d83e598d2277b8a945' 
  AND token = 'C6+sKTgHUzynq35QLpshOUg1Xh8YuLFtmo6/Jgvhagw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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