SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8285c5f72bb3052e2a595713250a223817428225ffd8cc9ef45719005f2317c5' 
  AND token = '2o+JdJiqnivSbmSe58HBP1KlqgtpHf4YF3vOz2nkSng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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