SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aac7c9d5ebcb359a81e76e5c1c2b345da5da01c15fd20f239a0c4e10b6505844' 
  AND token = 'Sh8/KLxOeU9Kf+5ApL+yJYTS701RxMuqJJjCZnRZDMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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