SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24e37270069109eb45989220e412408fe6e02092e141e3869f060c3a4cf80452' 
  AND token = 'UZisth4MFr0PBTSadsECeh9nfvTmsWmLX/VeFXABzpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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