SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fe4e177229525fefa9c0c7e1c75cf5e860b19cdc646530dca6c9098187c62e2' 
  AND token = 'IviM/+WM287G/TirrxRI4/rtqWSTt9HRKsaWQdf5Zm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}