SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bed0961b09a76b5d97662649b2016033add56592c9cc96ee2d977dd2e0e800ac' 
  AND token = '9fs43SXwVna9LMHeYSxTgcnN545wLpAljLGBxRW2ZXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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