SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a737c87de965c6deb14a68831cbea41468ede8e183f952f891cb1b808a0a6fed' 
  AND token = 'lM/sFoxocn98iFa9qeXpsvjo5yUDBTtTbr8r5UGdt5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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