SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53a215fee0164e50b98ab3afb36f1d543c24811b83dfcbfe2b24efef2f0dd61f' 
  AND token = 'h1blRebZByiqfvHQWOxBUWAS3WZHZ2qjHj2365bfGRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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