SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b4c702a6490715187126d0671807a836662bd6717bf88d579bfba2aabeafa69' 
  AND token = 'XGJlXVgudM+n5BueWW8VbCdUF8KB8qEHdr0tCeC3YWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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