SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0985a3adf316ef5f976e64c3c0d7bb9bcc1167bdef273cb73bdbcfe561ec54ba' 
  AND token = 'uV+smeHkcFl+Ajw9JJX3Rrk9G/iLnYCBRMMF8wPyqwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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