SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15ac59003b7ff7a5decc47e97415a18f23ed0822454d3a1f12ae7cedbf85966b' 
  AND token = 'ZNQpq5+BhCCRLf7QuPbx+y/XJd8+7pBuomasqkAth9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}