SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ccbe4f3e1a4e888247723f25e40724ddfd91022dfdb9a9559fefbbb6288ad3b' 
  AND token = 'BxWA9B7k1kN+Lb5kSgEUkDb/Fy+/zsZKQMJnAY2eyME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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