SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30adf784acad1e2aea80302bbe6e9eae0d0760835d82327e8d6faabdca72a7c2' 
  AND token = 'Azfoo+6R7L3OIZGoHStGWmcRmLpsZcpKLls9pZaDHrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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