SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '654c9b567adb0bdde2792fa0415c978839df4840e74f666d6162bf6eadc13d0a' 
  AND token = '9pPtSJZv8pFZlQLxk4txVq0VQWNzwNHA2m3z11ocYZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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