SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '529da5d68c11f40489ca24ab2cb5d6ee5aaa5a19468f8f840939676a729283b6' 
  AND token = 'WnGLc679ezbF9OY8k5D9oNWcJVE6xLmEbhg7MKNmVKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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