SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6df58b80cb669cd94b3e87ec882398c0a916d524570c73f2c54a7d5da652366e' 
  AND token = 'qfLE2hSSNmO5zY/XfDUEl8XEila1yKB+cYm5Jcz+tXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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