SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdfa667caeeac68f061cc36af11df4cbd799e56a5987fef839736ae9096d5fe5' 
  AND token = '842kTzZrtMs0Oa86NJmhtXRVQjd7OdfHSnvgxIPErEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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