SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd286f39cd62f352812cdf0412983f9ec5c4dec7fd2ea84147721d152e176f3e' 
  AND token = 'Lfoz1YhuO2FCGO1NBeADQMTkXe2PtSzO071/ZTwHM0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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