SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffaa25394044dd2804f054a94804028767b956b59cfc3f279d03303595f118f6' 
  AND token = 'bUbbhJkwcdlcVkZ5749hyZ0cKa9p5LciCsY/7s87Tps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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