SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b24015ba7ab19734538a33977d4f04217e1a187ede6fdbcdd6491ade29c3eef' 
  AND token = 'roRyX80JOdpax2+pw0QJ8QhFKir2TIQKJjppF67KkbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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