SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a943ce8e9e3f1bf07458e84cc0d623855723d5e39d0f5a4787143f2e7f7d9965' 
  AND token = 'TnIAZyVj2FvihO8i5P/DweVDrLmQgtapB+qfsHnhLC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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