SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cf358b27623bdd5421cd6a6ab02259c44a0c622020c56baf4e8e84640076b325' 
  AND token = 'NLYseLfS6VYuToe/vwjBJOxnoBSzDJ1PbVFA72syiZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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