SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '712625b4c96c6bd8cbb1ab67222b6087e92eb8ffb32a43b5cf6cf17818c4f97c' 
  AND token = 'WgQzjI+1tVEuiV5BMaIxCm7zYYBC5KA1xAF/6Bv1BMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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