SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68d6f8ea45d64e9cffbca7db8ae9b210c7c1d93f06f6d986a6e6aaecb94202f2' 
  AND token = '7WHy66Be/sHQE9sH96i54dpWxgbxvw8AcTGmKr72cRc=' 
  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"
    }
  }
}