SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbf7c7c01f34ecf978f506acc7c80a6360ebff51498c920c222043d0beda4f9a' 
  AND token = '7vaIbtyC2aoozV9KRfzuoRhtN4UZZRsVtXQ+pQQLzbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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