SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c090bfd67bebf7e1b2d1f51ecad114ee95f4e7ba6f6ac2708ae1016cdeba103' 
  AND token = 'p1RsjtpufkDu6qGewXXXcKOjeaFMpC6XbyGU6JN3Voc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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