SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2be028b324ff256fe949075e2125d9b816e5bed95aad334faed0ce0cd7b59ed6' 
  AND token = '81GpiLYpAovSqqw/LFK3dykq1yPNHYT+jVxqgXXZHyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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