SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0681d423b0640141e3cc65ed25db64f54982580f5c9f76edf424f3e09dc0af2a' 
  AND token = 'aYpjcIjpKPQHCHKx9WoE+JdXhzouv76DjwqrpvzUQPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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