SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8417430cb5aa4eb559adc45f1d00fec638a6f8ce92ae338b32fa35c02581a88a' 
  AND token = 'qPUF4diBC4hR3duwtmDq99475MvSx6+xyfRwHi8WbWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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