SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07b88bbf5347e5ec622ccde828c48267adf3dcd1ac07da0441a9372730eebe57' 
  AND token = 'BQjmxDBcHTIyv2/4FM33+eAmXwPzLSFMoEJKtRNTjds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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