SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65a453639b79f9a1e040f2231dc706d363050eb863b6c172697e4fba7e7b48c8' 
  AND token = 'z7xor3c1vZ/kIXU3M6tFsLaBqzDZEnnF78WDhSKInZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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