SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d84a78014d8eeb36303c93f59d693c3ee6b3c0fc039b9c4a9cf983d772bb4bc' 
  AND token = 'caedhpQrwI6cpNGE+kgqSFBWSK+lGAMRoKJPJMavQkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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