SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc834b1378e2af95eb13d07809dfef1578e73545ecc977af9bfbf6b6cc24bdf5' 
  AND token = 'rqmZV/u/EGyhxtXWhJMIZ3+aNv1bDmviEpQmQXzcJH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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