SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a28e96dd38b7dd2b35629631f2068c4a06d4287116c5ee780c7e40fd86664a4e' 
  AND token = 'DIONYQAvzRyrGZTcLFgvbemW9+hRmwJaUrltdBf4FKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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