SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a300b0b2f6a23c7461d22875122f247ce079ce1070bc8f515d293ddc7b7e3f1' 
  AND token = 'mooDWIEdF1+KFYaCYNUdL7w7lNHhrksxVGTziUB+6XQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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