SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fd79e706197b7dcce96adf53531bf6af3c86cced2ad09a76c2854125be97bc1' 
  AND token = 'JtWW4kQ3/VnfR/a2uvcvGm9+4BBhbZ9m6UKspJqVA20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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