SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'befc9f5822228f7613ff58f99847644adaaacaf824ceb057a3c9d083bf47d033' 
  AND token = 'BX1WMx6F7lt66azvDfHpOtcUbsXNS2G3/3FbPnPKEqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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