SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8e8cb39a7759e539ba52bc02e2e800a86f8777dafd31ec152b785e17d21d384' 
  AND token = 'dWjkgKA8BKmWuOdLxVC+yNA2jPXy6srW1l9Vs/4VwWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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