SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95a76970e3f9572c795a97992d859577c6a6ca5516054f202c3e9b399e5efdb9' 
  AND token = 'oyqO1aUh2ZQoYiEpR6GQjFtHYyIRwRhU3ZMtSjw4Y0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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