SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ede8d17d7490fbda95516d6616f7d69ae4c876194215f63c14a8b08a18ba3be4' 
  AND token = 'D51kn5rNKkz6VFibEQo5WSJQB3+mqg1zSfA8A8czeF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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