SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddd009825e99fd19eabec15a67b359eae1078d9150b7bc66e019bf5125e20c94' 
  AND token = 'wir5ebjbm8ZytuYi4o8n804sikjFyYSaRTW4mjpmruk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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