SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41eabcbb481f63bbacfad10ba200e5a07b2af06a7a7b52838cb940311824b934' 
  AND token = 'skD8hgiQVCmoLjOrYVzH9XRJ2XegrmRVhXZhvyBFKu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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