SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1468f60a6bbd341f9fe404738ad69e6b0ed1955840adb11496c14e318edd7ac' 
  AND token = 'Oqtnfox/Z4zHItTWsnYvFtNAi5GS87Ch0V9xQgZKRUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}