SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b41a2f1eb4a13f282ee312f2ad5925bfb2171567a9705723997f1545cd56b62b' 
  AND token = 'mSoFKtXGpeweGgU/nxXp/AgB7ShB15nncKTWIJMoLYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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