SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a3773cb6057d0bec6292cba4bc1af2741b60e4f97ff81216d44173b7ad6de1f' 
  AND token = 'bzAzpApVqxFI/T5YrIyZ+TQQlucD1L/jmUyKx1Cgwq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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