SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0e6e1aa9f9d5971d393172c3efac97013adf1a107fa51492306b6edb2a5e156' 
  AND token = 'lOAxDNErO68PufgKzmhNgJnVxbLr2PbaYM4JGMfjPwY=' 
  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"
    }
  }
}