SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '259578e0dfaedc677dbdcf6df2a77ea9a45c37c2a3e2f22657b1438ea83aa322' 
  AND token = 'BGsVL71y3NqCrnzN195Jlp9pBGnTQPacoWAsi5sq+GU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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