SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c8864d94863783d707b083491b1af222414140abd07b202481f493649c97995' 
  AND token = 'AwV1iXUKiC3b1mrOkUW5Tw7zUXLBgBxCnjnNm6CwNJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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