SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b7b57634b27ae5490129dad81efef40bc41e2ec8e1a5a8fafabefc029876eb3' 
  AND token = 'K2JpGAwPO0IsLGnfNyJwzeBEMOWsCfG23Mco2jZJy8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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