SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d203f078ca6cf1144db094302be58ad41dff642a579249eebe01024f650481b' 
  AND token = 'jNzP0jKRiIdMGl5St9XTaBBOKNEmfXT8h5MT1UCO9Kk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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