SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a8caf7a737b083c3220f44fa8af23289b95816c7828fea5340000c1b52d0e5b' 
  AND token = 'JAaM2bUzHlWNqOVXbiLknIsrishUb6Aza0/upnEYQlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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