SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64f60717a916dc484510ba24d142716bd6a6021b69aa1174233dd6cab29a9b1c' 
  AND token = '0H7j1NPbCHyPp9zEQVLQYJ9XUCeyGjuiifU1cmqDkIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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