SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1714c90af2e3175c0405d2d870f09efe771fe2a105c24bf3c64b48159178bbaf' 
  AND token = 'L9GMKfsvMwEJe9+I63xT/ZsZvaRj7QecOjkxdKVgZAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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