SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b0ff1edebe9737276b82675ab2e9913f0cfb6d74cad810721b116198a58bccb' 
  AND token = 'wAWFYGFvH1fF5VeMQdmFxy9+GcHo3wBP03A9OA1HNc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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