SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13c4e6cea358ccade088201dc102850bf60c577097c7e5c85f5f303b284db48f' 
  AND token = 'eadbAlYLzLz+qeudJbXu174dAp33xelFvJT65mhz3CA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}