SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dae9f2f0e70737b77e687efa6492f6250f66ded0907eae56aab68e8b46768f7c' 
  AND token = 'ilsl8uTc+85gIonVFf67o2peD+gAG2vIwGxRWBNPziU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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