SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ec049da6895cb243d14a05ebebda55217f44c259e802b1d28f48ace14038b659' 
  AND token = '7sjTz6bMvOd7jVS7STfdgVqo047/w+gWIcLJPi/xTKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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