SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83e0942db5030a21f50cc01a09d05ed78aac973a3ccc24ecf5d3d1919d3977ce' 
  AND token = 'BoKqKM9kJFF8MhBc8OYy+j0CMvGb6U+ENsparCi7OgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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