SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9131d5752f1dc85adbd8ccd549e45225a4623d128ef86ad9dbb0051832f36a83' 
  AND token = 'CSuUwMh8C+hIWWh+H4HhgwixkoMJ5q245LK2VNrjAp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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