SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69d6724a5b4da51f979651e6d69da2b1618e146d47f89dd7ba783f3c5de42c00' 
  AND token = '8olatwss6gQhGmUEV/U5dwCCFfbAw2eP/y0l7tXc3nQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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