SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9f01d50d174f4e5394cda6c27f5a2a9863440115b93ce17fb971ae9a8ca6e82' 
  AND token = '8F+AV4iow+7zDpKzD7fuOXivBkWxZWwp/Pikw1MU8h8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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