SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14f9a9ed8ebdf30d061170dadededee0b5429eefe79d93d40d661ade3ba55398' 
  AND token = 'oWybwMHz+11R7NPTXjVetPhDzaHABkgR2my+EoJaXxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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