SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d94c4b136a91eda62db4e57dd4885364c94568e7b49db982fa2dfd194f903f7' 
  AND token = 'sYdyfJdleEntWbZONjhmAeFGYv422ts1TzNvzGuJ1aA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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