SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '815f41b1abb75e139bed9d25e2ad5e26adab53547d07e35f0cc5a320682c04ee' 
  AND token = 'sj0JD5bBMQ4qh0FTA5TniHFgMcg2n5hAPCffQRL69DA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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