SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '632d53489b6370ac739379d098632161e7543f300e30792105f74301bd4c0dfc' 
  AND token = 'dR5CLLgURzcENOWP/5+fd9GdK3R//u9WtXvwH+vUAxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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