SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '815182850cd1f968566ed6a62400cb82631f5d7af4b9c38302880031c5a688f8' 
  AND token = '1lUPYAxBqWcSgf+iG/EsOPHlIFVcLyEzx2JjGCB/Q3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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