SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf6c5302f858b07b06684e33ca3d7921df9b348df8789ee4d3e6f254a25620ed' 
  AND token = 'O5WpoMxg7Kkb5YD4mBt5wYN/GsIUFOd3KcB+vpHDHm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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