SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4314ef7fad1c6f8c9c6bf14e13815803fb6559cf81548de24dfc05f820baa398' 
  AND token = '5aXJ6+BjpjiNYTQkRjMxEhYZAjFfRPO0g8v7UaFtIhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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