SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '73c98581fc5b94b9d8537d0719eb880774f0ac622071ef9ed5d9efbeea8529fb' 
  AND token = '1Yy6/kYwqZlSJSxp2DJ7KVKWeM06aj5dwKxFyATZL6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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