SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '224616b13760f64b83ce870d18c74b9e60d0a58d93d5cf40e2883673f87daddc' 
  AND token = '8Sc2bFo5uf+xmW0XFxZiIzdtZhvRx2sJNnK/O8+gjzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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