SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9cc733d44e88512913a3260e0723f70398793b7b6c718911995d507c8f74314' 
  AND token = 'IAbtTZ6CfQCV7qvEOKMVNTkwmWJxnPOOIv/aBFSOemU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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