SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fae88558fb6c7cdbeb951bddcfd6d7cf5ee1730aef6b59354c52d518708b26f' 
  AND token = 'r73qEjXOtszm3giRPvK9+f5jxH5svQw5X52tCpzojw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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