SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '363b69e0c74616b782de71cfc391c935c09d7ffe60f0b5088436bd1ec7003984' 
  AND token = 'a3UtTIuvJwN+60XR1qggLTmMoWFU9JiTd4pjBgb1xM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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