SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30002f63c204397e76c3aa8d24b1324058745c056519e2953efb029c3c737bce' 
  AND token = 'FE+J75HvXdNh5pgi3PmXGuLfIXAYbzXhzFRRQGvGCK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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