SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea7c58cb98fae15375d7f680d3ebc5f6f8dbb68e12d0aff0c329bdd3860f9d66' 
  AND token = '04zXXHImPV1FkS/fwrC/jwhdnJ4MZv4znkSuXNzu+9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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