SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f82884b2de2bf017bf1c04865aecc180e05c8df004d240017dca4e9fefe99bb7' 
  AND token = '9t6UnYwAQ+ugloOIK4cnqIh8MqHM2lo/vGOyEBL8oZY=' 
  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"
    }
  }
}