SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16b3b13a85bb45b500381ef88f0710e0816b837e48c999831caacb01a89929ff' 
  AND token = '/LyEZLIz5jVfLnlOS6ALoOilFRnpNDSnoBDHEDByX6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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