SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '190eb82c42f092cf629cd379e051bec7bbf67956beb2cedaac7f8b356d18d35d' 
  AND token = 'snbqL/2ebyQjbgW/qxpowF/Jaf7ADwpmE1vZiBKYwHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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