SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '268b139c5948e1bd40cac58918516a2ed8dcaa9b306af87a00168fc35306ceeb' 
  AND token = 'DBG5495cyjaRr/8advLTs2wwG9UMOCyVuDv2+TalIBM=' 
  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"
    }
  }
}