SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '825646951e568999083d2fc53f632ca1a7f47173ea13597431af6b33cf8f643c' 
  AND token = 'VwqgjYA4uzZAXJHwMSUF7Hz/5MRLCFrTap5dNA+Tn40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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