SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c3fe1d329c41c11c54e3809619ca385901bfe3569b50e7aeac0b61f13bffcef' 
  AND token = 'XauvCsjsEh2LYzDHFz6NE2OYyDvmIIwOMsZHUkBn0mI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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