SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6112ab35603d2d88e776911a64f1f1255ff478c112661832400c5b4e0233f798' 
  AND token = 'BOlbYLCtTb3zL5xaXNqjxh2BoNJL4XQCFIeuw2vgpSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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