SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3089cb0e944faa6caa70b9d9e32598a61fb38267d93f40f58c2a6e83f7dd8a9' 
  AND token = 'K/7bXj47F6V5DwvVpAAmvvj3RUsw34GAGFtFj/Q/B9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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