SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39e3accb98319f85238697a9e12fb8713ff4ed5eb7b556b8d1b98ce54f64cc95' 
  AND token = 'zQrNKDiA03KUDERFQCiDyg8BIW3Nl3O+8spEBBAKfto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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