SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0966e0e36512045dc8adaae5863ae816569a9d5fcafc6bd082dc781bf344277' 
  AND token = 'zGqwA/VGVkZnSR0kfz02P19FCrk5xszGzhyXExrxBxI=' 
  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"
    }
  }
}