SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72878de617ea94bbcce3ac084c26802460a892ec9654a8e6ebf329d6b0dd4f02' 
  AND token = 'CGyViyjkXlvDYjIyEpzxY8FgPUkeOzrKIyslr02KyYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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