SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca91daa3bde89f53dee7a7f40a82fe4039c345fb35f1348c3574837a41d04d5c' 
  AND token = 'pqdwDYrkltZS+ntPIB0fgwQS6WroFkXxQZUNGYZnPro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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