SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30de92201700c4baaed20c43547f3e29dcbc062c11385b0a18eb51bef0daf65a' 
  AND token = 'dc/aoSddwY4PDT/QIbUZdWkf8ClBgS0VkCgvmG8yUds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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