SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43f4c62e63940732a3a1c337abe6c66cfbb10f131ce81a42434ee9b8d4b8bf09' 
  AND token = 'wsWNQkUygNoZldqiAsoerkieKyo/QES3CdbZRYLzcr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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