SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd1824fb94a9a165975b0f37582db2c53cc33b276d2694e32946d21975d8e09f' 
  AND token = 'Bzy0IFE46qvBI/mkCPBYk88kXJAGz0fzSZlwCYJ7q8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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